Acromag BusWorks 900EN Series User manual

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Find the Acromag BusWorks 972EN-4004 at our website: Click HERE

BusWorks® 900EN Series –Modbus TCP/IP
10/100M Industrial Ethernet I/O Modules
Model 972EN-4004 Four Channel Current Output
Model 972EN-4006 Six Channel Current Output
Model 973EN-4004 Four Channel Voltage Output
Model 973EN-4006 Six Channel Voltage Output
USER’S MANUAL
TARGET DEVICE
ACROMAG INCORPORATED Tel: [phone]
30765 South Wixom Road Fax: [phone]
Wixom, MI 48393-2417 U.S.A.
Copyright 2003-2014, Acromag, Inc., Printed in the USA.
Data and specifications are subject to change without notice. 8500722J

BusWorks® 972/973EN Module User’s Manual Modbus TCP/IP Analog I/V Output
__________________________________________________________________
_______________________________________________________________________________________
Acromag, Inc. Tel:[phone] Fax:[phone] Email:[email protected] http://www.acromag.com
2
IMPORTANT SAFETY CONSIDERATIONS
You must consider the possible negative effects of power, wiring,
component, sensor, or software failure in the design of any type of
control or monitoring system. This is very important where property
loss or human life is involved. It is important that you perform
satisfactory overall system design and it is agreed between you and
Acromag, that this is your responsibility.
GETTING STARTED
MOUNTING AND DIMENSIONS………………………
3
CONTROLS & INDICATORS..…………………………
3
ISOLATION BARRIERS..……………………………….
3
CONNECTIONS………………………………………….
4
DIN-Rail Mounting And Removal………………
4
Network……………………………………………..
4
Power………………………………………………..
6
Analog Outputs…………………………………...
6
Earth Ground..………………………………….….
6
WEB BROWSER………………………………………...
7
Home Page…………………………………………
7
Password Configuration Page.………………...
8
Network Configuration Page……………………
8
I/O Mapping (Optional i2o Function)…………..
10
Test Page…………………………………………..
11
Calibration Page…………………………………..
12
Output Calibration………………………………..
13
TROUBLESHOOTING…………………………………..
15
Diagnostics Table……………………………..….
15
Trouble Browsing Your Module?.....................
16
Getting Out Of Trouble…………………………..
16
TECHNICAL REFERENCE
KEY FEATURES…………………………………………
17
HOW IT WORKS………….……………………………..
18
ABOUT MODBUS TCP/IP….…………………………..
19
IP Addressing…………..………………………….
19
Dynamic Host Configuration Protocol………..
21
Domain Name System (DNS)……………………
21
MODBUS REGISTERS…………………………………
21
Register Functions……………………………….
21
Register Mirroring……….………………………..
22
Data Types…………………………………………
23
Register Map………………………………………
24
SPECIFICATIONS……………………………………….
29
Model Numbers….………………………………..
29
Analog Outputs………………....…………………
29
General Specifications…………………………..
31
Enclosure and Physical………………………….
31
Agency Approvals…..…………………………….
32
Environmental……………………………………..
32
Ethernet Interface…………………………………
33
Controls & Indicators…………………………….
34
ACCESSORY CABLES…………………………………
34
REVISION HISTORY……………………………………
37
TABLE OF
CONTENTS
Symbols on equipment:
Means “Refer to User’s
Manual (this manual) for
additional information”.
The information of this manual
may change without notice.
Acromag makes no warranty
of any kind with regard to this
material, including, but not
limited to, the implied
warranties of merchantability
and fitness for a particular
purpose. Further, Acromag
assumes no responsibility for
any errors that may appear in
this manual and makes no
commitment to update, or
keep current, the information
contained in this manual. No
part of this manual may be
copied or reproduced in any
form without the prior written
consent of Acromag, Inc.
For additional information,
please visit our web site at
www.acromag.com and
download our whitepaper
8500-765, Introduction To
Modbus TCP/IP, or 8500-648,
Introduction to Modbus.
Windows® is a registered
trademark of Microsoft
Corporation.
!

BusWorks® 972/973EN Module User’s Manual Modbus TCP/IP Analog I/V Output
___________________________________________________________________
_______________________________________________________________________________________
Acromag, Inc. Tel:[phone] Fax:[phone] Email:[email protected] http://www.acromag.com
3
TB1
11 13 14 16 21
36
22
35
24
33
25
32
I 0+ I 1+
RTN RTN
I 3+
RTN RTN GND
I 5+ DC-
TB3
C
R S TD FT
LIN K
12
TB2
15 23 26
3134
LA C T
ST
3.75 (95.3)
TB1
RTN
3.90
(99.1)
I 2+
TB2
RTN
I 4+
A N A LO G O U TP U TS
P W R
DC+
1.05
(26.7)
4.68 (118.9)
RU N
TB3
2.34 (59.4)
"T"RAILDIN MOUNTING
DIN EN 50022,35mm
E TH E RN E T
Acromag
4.35
(110.5)
Model
972EN-4006 Only
NOTE:DimensionsAreINCHES (MILLIMETERS).
MODEL972/973ENENCLOSURE DIMENSIONS
A N A LO G O U TP U TS
Model 972EN-4006
(Models 972EN-4004, 973EN-4006,
and 973E N-4004 ar e sim ilar )
RST
11 12 14 15 22
35
23
34
25
32
26
31
ACT
ST
I 0+
RTN RTN
I 2+
TB2
RTN
I 4+ I 5+ DC-
RTN DC+
LINK
TB1
13 16 21 24
36 33
TB1
I 1+
RTN
I 3+
RTN
ANALOG OUTPUTS
GND
PWR
TB3
TB3
ETHERNET
DFT
RUN
TB2
(PLUG-INTYPE)
TERMINALBLOCKS
RJ45ETHERNET
CONNECTOR
ETHERNETACTIVITY
LED(YELLOW)AND
LINK LED(GREEN)
Acromag
RUN/PWRLED(GREEN)
Model
972EN-4006Only
REMOVABLE
RESET/DEFADDRESS
TOGGLESWITCH:
TOGGLERIGHTTORESET
TOGGLELEFTTOSET
DEFAULTADDRESS
MODULE STATUS
LED(YELLOW)
ANALOG OUTPUTS
Model 972EN-4006
(Models 972EN-4004,973EN-4006,
and973EN-4004aresimilar)
12 15
I2+
23
I4+
26
RTN
RX
TX
TB2
34
RTN DC+
31
11
I0+
13 1614
I1+
21 2422 25
I3+ I5+
5V/3V
TB3
TB1
TB1
RTN RTN RTN RTN
36 33
GND
35
DC-
32
EARTH
GROUND
TB3
NETWORK
ANALOGOUTPUTS
TB2
ANALOGOUTPUTS
TRANSFORMER
972/973EN
ISOLATION
DIAGRAM PWR
DC
PWR
ANALOGOUTPUTS
TRANSFORMER
ANALOGOUTPUTS
The toggle switch is used to toggle the module into or out of Default Mode
(toggle left), or to reset the module (toggle right). In Default Communication
Mode, the yellow ST LED blinks slowly and the module assumes a fixed
static IP address of “128.1.1.100”, a default subnet mask of “255.255.255.0”,
a default username of “User”, and a default password of “password00”.
MOUNTING AND
DIMENSIONS
Unit mounts to “T” type DIN
rails (35mm, type EN50022).
Units may be mounted side-
by-side on 1-inch centers.
WARNING: IEC Safety
Standards may require that
this device be mounted within
an approved metal enclosure
or sub-system, particularly for
applications with exposure to
voltages greater than or equal
to 75VDC or 50VAC.
CONTROLS &
INDICATORS
Green Run LED is ON if power
is on and will blink in “wink” ID
mode.
Yellow ST LED blinks ON/OFF
if module is in default mode
and blinks more rapidly
following a watchdog timeout.
Green LINK LED is ON if auto-
negotiation has successfully
established a connection.
Yellow ACT LED signals PHY
network Activity (busy).
ISOLATION BARRIERS
Dashed Lines denote isolation
barriers.
The output circuit, network,
and power circuit are isolated
from each other for safety and
noise immunity.

BusWorks® 972/973EN Module User’s Manual Modbus TCP/IP Analog I/V Output
__________________________________________________________________
_______________________________________________________________________________________
Acromag, Inc. Tel:[phone] Fax:[phone] Email:[email protected] http://www.acromag.com
4
45 44 42 41 33
DC+
31
12 13 15 16 21 23 24 26
TB1
GND
46 43
PWR
DC-
32
11 14 22
TB4
25
TB3TB3
PUSH
TB2
"T" TYPE
DIN RAIL
Any Series 9XXEN Ethernet Module
PUSH SCREWDRIVER AS SHOWN
TO TILT AND LIFT MODULE OFF RAIL
Remove Terminal Blocks On This
Side To Provide Clearance
MODULEREMOVAL
FROM DIN RAIL
PRY WITH SCREWDRIVER
INSERTED IN SLOT HERE
(DO NOT TWIST TO AVOID
DAMAGING PLASTIC TAB)
USE YOUR FINGER TO APPLY
DOWNWARD PRESSURE HERE
AS YOU LIFT AND TILT MODULE
TO REMOVE IT FROM RAIL
1
8
5
6
2
3
100M
CABLE
8
18
7
4
1
100M
CLIP
100Base-T
SPEED DISTANCE
RECOMMENDEDCABLE
Not Used
Not Used
Receive -
Transmit -
Receive +
PIN MDI WIRING
10Base-T
Not Used
Not Used
Transmit + ETHERNET PORT
CAT 5/5e UTP/STP
Not Used RJ-45CONNECTOR
Not Used
Transmit -
Receive -
Transmit +
MDI-X WIRING
RJ45 MDI ANDMDI-X CONNECTIONS
Not Used
Not Used
CAT 3, CAT 4, orCAT 5 UTP
NoteCrossoverConnections
Receive +
When attaching the module to the
T-type DIN rail, angle the top of the
unit towards the rail and locate the
top groove of the adapter over the
upper lip of the rail. Firmly push the
unit towards the rail until it snaps into
place. To remove, first separate the
input terminal block(s) from the
bottom side of the module to create a
clearance to the DIN mounting area.
Next, while holding the module in
place from above, insert a
screwdriver into the lower arm of the
DIN rail connector and use it as a
lever to force the connector down
until the unit disengages from the rail
(do not twist the screwdriver to avoid
damaging plastic).
The Ethernet port of this module is wired MDI and does not include
automatic crossover. The Ethernet port of your PC is also wired MDI and
may not include automatic crossover. As such, you must use a crossover
cable like that shown below when connecting this device directly to a PC.
1
1
3
6
1
6
2
3
1
8
281
8
8
1
PINS: 1TO 3
2TO6
3TO1
6TO2
RJ45(ClipSideDown) RJ45(ClipSideDown)
FOR DIRECTPC TO
ETHERNETMODULE
CONNECTIONS
CROSSOVER CABLE
FOR MDI TO MDI
OR MDI-X TO MDI-X CROSSOVER
CONNECTIONS
CONNECTIONS
DIN-Rail
Mounting & Removal
Network
For 100Base-TX systems, use
data grade Unshielded
Twisted-Pair (UTP) wiring that
has a 100Ω characteristic
impedance and meets the
EIA/TIA Category Five wire
specifications.
It is recommended that you
use a crossover CAT-5 cable
to connect this device to your
PC.
For 10Base-T systems, you
may use Category 3, Category
4, or Category 5 UTP cable.
In either case, you are limited
to 100 meters between any
two devices.
A crossover cable simply
connects the differential
transmit pair on each end, to
the receive pair on the
opposite end.
Use a standard (direct) cable
when connecting to a hub or
switch port, which are
generally wired MDI-X.

BusWorks® 972/973EN Module User’s Manual Modbus TCP/IP Analog I/V Output
___________________________________________________________________
_______________________________________________________________________________________
Acromag, Inc. Tel:[phone] Fax:[phone] Email:[email protected] http://www.acromag.com
5
S1 S2
DC-
33
DC+
32
RS
109
65
21 3
98
54
10
DA
11
7
2 3
ST
8
4
0
10
76
2 3
ST
98
54
10
DA
11
7
2 3
ST
100M
LK /
P1
X3 X4
TB 3
CH. I / O STATUS
ACT
ACT
CH. I / O STATUS
RUN
X5
X5
X4
X1
GND
34
DC+
31
8
4
0
RUN
DA
LI NK
11
7
ST
LI NK
10
6
DARS
LI NK
911
5
1
RS
LI NK
10
6
RUN
COL
ACT
X5
X3
X2
X1 X2
PG M
PO RT
PUSH TO RESET
ACT
ACT
ETHERNET
Ac ro m a g
CH. I / O STATUS
CH. I / O STATUS
PO WER
RS
RUN
RUN
ETHERNET
SW I TCH
Ac ro m a g
ETHERNET
ETHERNET
Ac ro m a g
Ac ro m a g
ETHERNET
Ac ro m a g
HOSTPC
Acromag9xxEN-4012
EthernetModules.
Theethernetportofthese
modulesarenotautomatic
MDI/MDI-X crossover, but
theuseofanauto-crossing
switcheliminatestheneed
tomakeadistinctionbetween
straight-throughandcrossover
cables.
(Straight-ThroughorCrossoverCable)
CAT-5UTP CABLE
UP TO100METERS
(Straight-ThroughorCrossoverCable)
OrderAcromagCableModel 5035-355
CAT-5UTP CABLE
UP TO100METERS
ETHERNET
SWITCH
DI P SW S1/ S2
CFG O PTIO NS
CAT-5UTP CABLE
UP TO100METERS
(Straight-ThroughorCrossoverCable)
(Straight-ThroughorCrossoverCable)
CAT-5UTP CABLE
UP TO100METERS
CAT-5UTP CABLE
UP TO100METERS
TheethernetportofthePCis
generallynotautomaticMDI/MDI-X
crossoverandis wiredMDI.
BecausetheAcromagethernetswitch
900EN-S005isautomaticMDI/MDI-X
crossover,useofadirect(straight-through)
orcrossovercableispermissible.
IMPORTANT: IFTHE HOSTPC CONNECTS DIRECTLY TOTHE MODULE,
YOUMUSTUSE A CROSS-CONNECTCABLE (MDI-X),AS BOTH THE PC
ANDTHE 9XXEN MODULE ETHERNETPORTS ARE WIREDMDI.
ETHERNETSWITCHES ANDHUBS ARE WIRED MDI-X.
THE ACROMAGETHERNETSWITCHIS AUTOMATIC MDI/MDI-X AND
ELIMINATES THE NEEDFOR MAKINGA DISTINCTIONBETWEEN
THE USE OFSTRAIGHT-THROUGH (MDI)ANDCROSSOVER (MDI-X)
CABLE CONNECTIONS.
Acromag900EN-S005
5-PortEthernetSwitch
orequivalent.
Theethernetportsofthis
switchareautomaticMDI/MDI-X
crossinganddonotrequire
crossovercables.
USE OF AN ETHERNET SWITCH TO NETWORK
A HOST PC TO MORE THAN ONE MODULE
Acromag offers a straight-through patch cable (Model 5035-355), or a
crossover cable (Model 5035-360) for use with Series 9xxEN modules.
ST
DFT RST
LI NK
RUN
ETHERNET
ACT
Ac ro m ag
HOSTPC
(UseCrossoverCable)
HOST PC CONNECTED DIRECTLY TOA MODULE
Note:ThisMDI-to-MDIconnectionrequirestheuseofacrossovercable.
CAT-5UTPCABLE
UPTO100METERS
OrderAcromagCableModel5035-360
Refer to the Accessory Cables section at the back of this manual for more
information on accessory cables, including patch and crossover cables
available from Acromag and other vendors.
TIP: You can significantly enhance the EMI/RFI performance of your
network connections by using Category 5E STP cable (Shielded Twisted
Pair) with shielded RJ45 plug connectors. This will also help to protect your
installation from damage due to ESD (Electro-Static Discharge). The use of
shielded cable is strongly recommended for installations in harsh industrial
environments and/or in the presence of strong electrical fields.
You can use an Ethernet switch or switching hub to build a network of
Ethernet modules, similar to that shown below. This drawing shows how to
network-connect Acromag Series 9xxEN modules to a 5-port Ethernet
switch (Acromag Model 900EN-S005). Note that the 900EN-S005 switch
includes automatic MDI/MDI-X crossover and a straight-through or
crossover cable(s) may be used to connect to the modules and the PC.
CONNECTIONS
Network

BusWorks® 972/973EN Module User’s Manual Modbus TCP/IP Analog I/V Output
__________________________________________________________________
_______________________________________________________________________________________
Acromag, Inc. Tel:[phone] Fax:[phone] Email:[email protected] http://www.acromag.com
6
L
16 15 13 12 16 14 13 11
L
14 11 15 12
R
TB1
RTN
V 2+
V 1+
RTN
RTN
RTN
I1+
I0+
R
I
TB1
RTN
V 0+
I2+
RTN
+
+
ANALOGOUTPUTS
ANALOGOUTPUTS
OUTLOAD
CURRENT
GROUND
TB1
TB1
SHIELDED CABLE
(UPTO 10mA)
VOLTAGE
OUTLOAD
EARTH
SHIELDED CABLE
EARTH
GROUND
(UPTO 550OHMS)
CHANNEL1 OF6
VOLTAGEOUTPUTCONNECTIONS(973EN)
CURRENTOUTPUT CONNECTIONS(972EN)
CHANNEL1 OF6
✓Connect 15-36V DC to the power terminals labeled DC+ & DC-.
Observe proper polarity. For supply connections, use No. 14 AWG
wires rated for at least 75C. CAUTION: Do not exceed 36VDC peak.
33 31
DC+
32
DC-
PWR
+
TB3
GND
TB3 INPUT POWER
IS ISOLATED
EARTH
GROUND
15 TO 36VDC
CAUTION: Risk of Electric Shock –More than one disconnect switch may
be required to de-energize equipment before servicing.
IMPORTANT –External Fuse: If unit is powered from a supply capable of
delivering more than 1A to the unit, it is recommended that this current be
limited via a high surge tolerant fuse rated for a maximum current of 1A or
less (for example, see Bel Fuse MJS1).
✓Connect analog outputs at the output terminals as shown below
according to your model.
✓Connect Earth Ground as shown in the connection drawings above.
Additionally, connect the GND terminal (TB3-33) to earth ground.
The ground connections noted are recommended for best results. If
sensors are already grounded, use caution and avoid making additional
ground connections which could create ground loops.
The plastic module housing does not require earth ground.
CONNECTIONS
Power
Voltage
Current
972EN-4006
15VDC
312mA
18VDC
255mA
24VDC
189mA
36VDC
128mA
973EN-4006
15VDC
140mA
18VDC
117mA
24VDC
89mA
36VDC
65mA
Analog Outputs
Output is DC Current (972EN)
or DC Voltage (973EN).
Outputs are not isolated
channel-to-channel and share
a common return (RTN).
Current outputs may drive up
to 21mA into 500Ω (972EN).
Voltage outputs may deliver up
to 10V into 1KΩ, or 10mA
(973EN).
Earth Ground
Warning: To comply with
safety and performance
standards, use shielded cable
and connect earth ground as
noted. Failure to use good
wiring and grounding practices
may be unsafe and hurt
performance.

BusWorks® 972/973EN Module User’s Manual Modbus TCP/IP Analog I/V Output
___________________________________________________________________
_______________________________________________________________________________________
Acromag, Inc. Tel:[phone] Fax:[phone] Email:[email protected] http://www.acromag.com
7
This module supports Modbus over TCP/IP. You may use your own
software to issue Modbus command to this module (see Modbus Registers),
or you may use a standard web browser, as these modules have built-in web
pages that allow you to setup, control, and calibrate the module. Simply
execute your web browser, type the IP address assigned to your module in
the “Address” window (http://128.1.1.100/ for our example), click [Go], and
you will be presented with a Home Page window similar to that shown below:
The Home Page provides buttons to access the other web pages of this
module that are used to configure the network parameters, change the user
name and password, calibrate the module, and operate/test the module.
For each new browser session that accesses the Home Page of this
module, you will be presented with a window prompting you to enter the
current User Name and Password as shown below. This information is
required before the program will allow you to make any other selections.
The default user name and password is “User” and “password00”
respectively. After entering these defaults, you may wish to invoke the
Password Configuration Page to change these parameters to something
more meaningful to you. Note that these entries are case-sensitive.
IMPORTANT: If you forget your
installed user name & password,
you can always toggle the
module into default mode via the
default mode toggle switch at
the front of the module. Then
the password and username will
revert to the original defaults
noted above, allowing you to re-
invoke the Password
Configuration Page and change
the username and password
settings as required.
WEB BROWSER
Home Page

BusWorks® 972/973EN Module User’s Manual Modbus TCP/IP Analog I/V Output
__________________________________________________________________
_______________________________________________________________________________________
Acromag, Inc. Tel:[phone] Fax:[phone] Email:[email protected] http://www.acromag.com
8
After completing your username/password changes, click on the appropriate
button at the bottom of the page to select another web page. If you made
changes, you may be prompted to re-enter your new username and
password before being permitted to move to other pages.
After setting your username and password, you can click the “Network
Configuration Page” button to set the network configuration parameters for
the module. You may have to consult your network administrator for help to
complete the contents of this page.
WEB BROWSER
Password
Configuration Page
Use up to 20 alphanumeric
characters (case sensitive) to
specify your username, and 10
alphanumeric characters (case
sensitive) to specify a
password. You will have to
type in these entries twice to
help prevent errors (yes, I
know this is annoying).
Click the submit button to
write your changes to the
module.
Network Configuration

BusWorks® 972/973EN Module User’s Manual Modbus TCP/IP Analog I/V Output
___________________________________________________________________
_______________________________________________________________________________________
Acromag, Inc. Tel:[phone] Fax:[phone] Email:[email protected] http://www.acromag.com
9
An IP Address is a unique identification number for any host (this module)
on any TCP/IP network (including the internet). The IP address is made up
of four octets (8 bits), each octet having a value between 0-255 (00H-FFH).
It is expressed here in decimal form, with a period placed between octets.
A Static IP Address is as the name implies—static, and represents a unique
fixed IP Address that is generally assigned by your service provider or
system administrator. The default static IP address assigned to this module
from the factory is 128.1.1.100 (refer to product side label).
NOTE: In order to network your PC with an Acromag module, you may have
to consult with your network administrator and either temporarily change
your TCP/IP configuration (see TCP/IP Properties of Network Configuration
in Windows), or create a separate private network using a second network
adapter installed in your PC (recommended). The necessary steps will vary
with your operating system. Refer to Acromag Application Note 8500-734 to
help accomplish this (located on the CDROM shipped with your module or
via download from our web site at www.acromag.com).
The Number of Sockets refers to the number (1-10) of Modbus TCP/IP
access points to allow for this host. The default allows up to 10 sockets, but
you can restrict access by reducing this number. Internally, the module uses
port number 502 which is reserved for Modbus.
The DNS Server refers to the IP address of the Domain Name Server used
on this network. A DNS server relates symbolic names to actual IP
addresses, while the DHCP server is responsible for dynamically passing out
IP addresses.
A Subnet Mask is used to subdivide the host portion of the IP address into
two or more subnets. The subnet mask will flag the bits of the IP address
that belong to the network address, and the remaining bits correspond to the
host portion of the address. The unique subnet to which an IP address
refers to is recovered by performing a bitwise AND operation between the IP
address and the mask itself, with the result being the sub-network address.
Gateway refers to the IP Address of the gateway, if your local area network
happens to be isolated by a gateway. Typically, it is assigned the first host
address in the subnet. If a gateway is not present, then this field should
contain an unused address within the host subnet address range.
The Host Name is the name to be assigned to this host if its address
happens to be assigned dynamically using DHCP.
The Active IP Address refers to the current IP Address being used by this
host, as opposed to any new assignments being made via this page.
The MAC Address refers to the Media Access Control Address that
uniquely identifies the hardware of this device. This is a unique fixed
address assigned to this module at the factory. On IEEE 802 networks, the
Data Link Control (DLC) layer of the OSI Reference Model is divided into two
sublayers: the Logical Link Control (LLC) layer, and the Media Access
Control (MAC) layer. The MAC layer interfaces directly with the network
media (each different type of network media requires a different MAC layer).
WEB BROWSER
Network Configuration
Note that Acromag Series
9xxEN Ethernet I/O modules
may take from 3-30 seconds to
boot upon power-up,
depending on your network
configuration and whether a
DHCP server is present.
This module can be placed
into a default communication
mode via the DFT toggle
switch at the front of the
module.
Default Mode uses a static IP
address of “128.1.1.100”, a
default subnet mask of
“255.255.255.0”, a default
username “User”, and a
default password
“password00”.

BusWorks® 972/973EN Module User’s Manual Modbus TCP/IP Analog I/V Output
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By default, the module is setup to use Static IP Addressing and a Static IP
Address of 128.1.1.100. You can optionally choose to have the IP address
assigned dynamically via DHCP/BOOTP, or DHCP/BOOTP w/Fallback. This
will also require that you specify a valid Host Name. Note that
DHCP/BOOTP w/Fallback will revert to the static IP address if your DHCP or
BOOTP server cannot be found at the address specified.
In general, BOOTP (Bootstrap Protocol) refers to an internet protocol that
enables a diskless workstation to discover its own IP address, the address of
a BOOTP server on the network, and a file to be loaded into memory to boot
the machine. This enables the workstation or device server to boot without
requiring a hard or floppy disk drive. BOOTP works similar to DHCP, but is
usually found in older systems. This protocol is defined by RFC 951.
DHCP (Dynamic Host Configuration Protocol) refers to a protocol for
assigning dynamic IP addresses to devices on a network. With dynamic
addressing, a device can have a different IP address every time it connects
to the network. In some systems, it can even change while it is still
connected. DHCP also supports a combination of static and dynamic IP
addresses. DHCP/BOOTP with fallback will revert to static IP addressing if
the DHCP or BOOTP server cannot be found.
The unit includes a default address toggle switch to cause the module to
assume a preset default factory address. This switch is at the front of the
module and is used to toggle the module into, or out of Default Mode. If you
use the toggle switch at the front of the module to place the module in
default mode, then “Default Communications Mode” will be indicated at the
bottom of this screen.
Click the Submit button to complete any changes made on this page.
Click the Wink On/Off button to toggle the module in/out of “wink” ID mode.
In this mode, the module’s green RUN LED will blink to confirm identification
as an aide to locating a specific module on a network.
Refer to the Technical Reference section of this manual to learn more about
IP Addressing terms and concepts.
The 972EN-4006 and 973EN-4006 analog output models are target output
devices for Acromag 9xxEN input modules with input-to-output mapping
capability. That is, i2o equipped input modules may be configured to write
their input levels to compatible output modules via the network connection.
Acromag 961EN-4006, 962EN-4006, 965EN-4006, and 966EN-4006 input
modules may be configured to control the outputs of these models.
WEB BROWSER
Network Configuration
The Default Communication
Mode uses a static IP address
of “128.1.1.100”, a default
subnet mask of
“255.255.255.0”, a default
username of “User”, and a
default password of
“password00”.
I/O Mapping
(Optional i2o Function)

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After completing your username & password assignment, plus your network
configuration parameters, you can use the Test Page to operate your
module. The Test Page will allow you to write the outputs, change your
output range, and configure your watchdog parameters.
Use the scroll bar on the right to scroll down the page as shown below:
You can also use the Configuration Control of this page to change the output
range for each channel. For the 973EN shown, you may select 0-10V, 0-5V,
or 0-1V. For the 972EN, you may select 0-20mA, 4-20mA, or 0-1mA. You
may also set your watchdog time and output timeout level. Click on “write
range and watchdog settings” to execute your changes.
WEB BROWSER
Test Page
TIP: Viewing a module’s web
page is treated similar to
viewing a web page on the
internet. The first time you
open a page, its image is
stored as a temporary internet
file in PC memory. However,
each subsequent attempt to
view that page will need to
automatically update that
image, especially when
making configuration changes.
With Internet Explorer, click
the “Internet Options” of the
“Tools” menu, select the
“General” tab, locate the
“Temporary Internet Files”
information and click on the
“Settings” button. Then select
“Automatically” under “Check
for newer versions of stored
pages:”. Then click [OK] to
return to the “General” screen,
and click [OK] again to save
your settings.
IMPORTANT: The input
signal indicated only reflects
the level of the outputs at the
moment this screen is invoked
and this does not continuously
update. You can click your
browser’s refresh button to get
a new output update.

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The Calibration Page will allow you to recalibrate each channel’s output zero
and span signal as required. Simply select the channel to be calibrated.
Choose zero or span and set the output. Measure the zero or full-scale
endpoint signal and enter this value in the space provided. Then click
calibrate. Repeat this procedure for the other endpoint, and other channels,
as required. For best results, always calibrate zero before span.
Use the scroll bar on the right to scroll down the page as shown below:
The following table gives the calibration values for the base output range of
these models.
WEB BROWSER
Calibration Page
IMPORTANT: This module
has already been calibrated at
the factory and recalibration is
not normally required, except
as necessary to correct for
long term component aging, or
to satisfy your company’s
maintenance requirements.
Do not attempt to recalibrate
this module unless absolutely
required, as miscalibration will
negatively affect the module’s
performance.

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Your success in recalibrating the output will strongly depend upon the
accuracy and precision of your measurement system.
Cal LOW (Zero)
Cal HIGH (Full-Scale)
Model
Range
Signal
~Write %
Signal
~Write %
972EN
4-20mA
4.000mA
0
20.000mA
20000
973EN
0-10V
0.000V
0
10.000V
20000
Notes:
1. With 16-bit signed integers, a count of 0-7FFFH is a positive number,
while 8000-FFFFH is a negative number. The 0-10V DC output range
values are represented by 0-20000 counts. For example when using a
973EN, 0V and 10V are represented by integer values 0 & +20000,
respectively.
2. For calibration via the Modbus TCP/IP interface, the “Write %” values
noted above are the ideal values written to the output word of the
channel and may only approximate the actual value required to produce
the actual calibration endpoint signals. During calibration, you will need
to adjust these values to precisely reproduce the endpoint signals. For
calibration via the web browser, “Write %” values noted above are
actual values written to the output word of the channel during
calibration. Uncalibrated, they approximate the required endpoint
signal. Your measured value is then used to adjust the count values as
required to precisely reproduce the endpoint signals.
3. Calibration of the current (0-20mA, 0-1mA), and voltage (0-5V, 0-1V)
subranges are internally interpolated from the resultant calibration of the
base range noted in the table above for each model. Additionally, since
resolution is degraded for the sub-ranges, it is very important that high
accuracy be ensured for the primary base calibration when making
output adjustments and measurements, as subranges are linearly
interpolated from these results.
The Series 972/973EN output modules are calibrated using a single base
output range with fixed calibration endpoints. The calibration of the module’s
sub-ranges are automatically interpolated based on these results. Prior to
calibration, the 972EN models must have the 4-20mA output range selected,
and the 973EN must have the 0-10V output range selected. Calibration is
then performed by adjusting the output signal level until its measured value
precisely matches the low or high calibration range endpoint indicated. With
the output level precisely adjusted to the Calibration LOW or HIGH range
endpoint signal, the module is triggered to store the output channel’s raw
DAC count by toggling the corresponding channel’s Cal HIGH (upper byte)
or Cal LOW (lower byte) calibration register.
You can choose to use the web browser calibration page (Method 1) to
accomplish calibration (easiest), or via direct register access using the
Modbus TCP/IP interface as described in Method 2 below:
IMPORTANT: For best results, you must measure the output signal via an
external current or volt meter that is at least as accurate as the module itself
(better than ±0.1% of span). Always calibrate the low value before the high
value and allow the module to warm up a few minutes prior to calibration.
WEB BROWSER
Calibration Page
Output Calibration

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Method 1 –Calibration Using The Built-In Browser Interface:
1. Make sure the base output range is currently selected. This is 4-20mA
for 972EN models, or 0-10V for 973EN models. You can go back and
use the Test Page controls to change the output range as required.
2. Bring up the browser interface and select the Calibration Page.
3. Select an output channel, then select Zero.
4. Click the “Set Output” button and an “ideal” zero count will be written to
the DAC. The output will go to approximately zero.
At this point, you will lose control of the output and must complete the
procedure, or simply click “restart calibration” to start over. If you picked
the wrong output channel, or the wrong endpoint, click “restart
calibration” to start over.
5. With a meter connected to measure the output signal, measure the
actual output level and enter this value into the edit box labeled “DVM
Reading”. Then click the “Calibrate” button to complete calibration of the
zero endpoint.
6. Next select Span (for best results, always calibrate zero before span).
7. Click the “Set Output” button and an “ideal” full-scale count (20000) will
be written to the DAC. The output will go to approximately full-scale.
At this point, you will again lose control of the output and must complete
the procedure, or simply click “restart calibration” to start over. If you
picked the wrong output channel, or wrong endpoint, click “restart
calibration” to start over.
8. With a meter connected to measure the output signal, measure the
actual output and enter this value into the edit box labeled “DVM
Reading”. Then click the “Calibrate” button to complete calibration of the
full-scale endpoint.
9. Repeat steps 3-8 for the other output channels to be calibrated.
Method 2 - Calibration Via The Modbus TCP/IP Interface:
1. Write to the appropriate Output Range Register to select the output base
range for each channel to be calibrated. Select 4-20mA for 972EN
models, or 0-10V for 973EN models.
2. Write 24106 (5E2AH) into the Calibration Access Register to remove
write protection from the calibration registers.
3. Write the zero calibration % value to the output to be calibrated and
adjust this value as necessary to precisely reproduce the Cal LOW
(zero) signal (see table of prior page). Allow the output to settle a few
seconds.
4. Write a 16-bit value to the Zero Calibration Register with a set bit in the
bit position that corresponds to the channel number to be calibrated (one
channel at a time). If you were calibrating the zero of channel 5, you
would write 0x0010 to the Zero Calibration Register. The module will
replace calibration coefficients immediately, no reset needed.
5. Write the full-scale calibration signal % value to the output to be
calibrated and allow the output to settle about 10 seconds.
6. Write a 16-bit value to the Span Calibration Register with a set bit in the
bit position that corresponds to the channel number of the channel to be
calibrated (one channel at a time). For example, if you wanted to
calibrate the span of channel 0, write 0x0001 to the “Span Cal Register”.
Note that the calibration of the output sub-ranges are automatically
interpolated based on the calibration of the base range just completed.
Output Calibration

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Method 2 - Calibration Via The Modbus TCP/IP Interface…continued:
7. Repeat steps 3-6 for the other output channels as required.
8. When finished calibrating, write 0x0000 to the Calibration Access
Register to replace write protection for the calibration registers and help
prevent miscalibration.
You may then check the calibration of the alternate range(s) for the
output(s). Note that the alternate ranges are calibrated by interpolating
their calibration endpoints from those of the base range. If significant
error is noted, then you must perform the calibration procedure a second
time, making sure that you precisely adjust your output signal for zero
and span as required.
Upon power-up, the green RUN LED should light. A continuous blinking Run
LED indicates “wink” ID mode. If the Run LED remains OFF and correct
power has been applied, then either the internal power supply has failed or a
fatal processor error (firmware) has occurred.
SYMPTOM
POSSIBLE CAUSE
POSSIBLE FIX
Green RUN LED
does not light.
Internal +3.3V power
has failed.
Return module for repair.
Continuous flashing
green RUN LED.
Module in “wink”
mode.
Read Module Status register
to verify “wink” status. Write
5555H to Wink Mode
Toggle Register to toggle
wink mode off/on.
Cannot
communicate.
Power ON at the
module?
Check power. Is green
RUN LED ON?
Connecting cable is
not a crossover
cable.
TIP: To check cable
type, hold both ends
in same position and
read the wire colors
through the clear
portion of the plug
from left to right. If
colors are arranged in
the same order, you
have a straight cable.
This module’s ethernet port
is wired MDI. You must use
a crossover cable when
connecting this module to
your PC or another device
also wired MDI. If you are
connecting to an Ethernet
switch or hub, then a direct
cable is used.
Note: If your Link LED is
ON, you have connected
using the correct type of
cable, but it could still be
defective.
Wrong IP Address
Change the IP address of
module or PC so that both
match. Try default module
address of 128.1.1.100. For
the PC NIC, try using
another address.
Cannot Browse
Module.
Your browser may be
setup to use a proxy
server for LAN
communications.
Temporarily disable the use
of a proxy server by your
browser (see procedure of
next page).
Output Calibration
TROUBLE-
SHOOTING
Diagnostics Table
If your problem still exists after
checking your wiring and
reviewing this information, or if
other evidence points to
another problem with the unit,
an effective and convenient
fault diagnosis method is to
exchange the module with a
known good unit. Acromag’s
Application Engineers can
provide further technical
assistance if required.
Complete repair services are
also available from Acromag.

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SYMPTOM
POSSIBLE CAUSE
POSSIBLE FIX
Many
Communication
Errors.
Is cable segment
longer than 100M?
Maximum distance between
two nodes is limited to 100
meters using approved
cable.
Correct Cable?
Shielded CAT-5/5E cable or
equivalent is recommended.
Missing earth ground
connection.
Connect earth ground to
TB3-33 GND terminal
adjacent to power terminal.
Please refer Acromag Application Note 8500-734 for help in setting up
network communication with your module (located on the CDROM shipped
with your module or via download from our web site at www.acromag.com).
This document gives details for changing your PC’s TCP/IP configuration in
order to communicate with your module (see TCP/IP Properties of Network
Configuration in Windows).
If you have carefully followed this procedure and you still cannot browse your
module, you may have the web browser of your laptop or PC setup to use a
proxy server when browsing the web. If you are using Internet Explorer,
Refer to the “Tools” pulldown menu, select “Internet options…”, click the
“Connections” tab, then click the “LAN Settings” button. Locate the Proxy
server information and uncheck the box next to the statement “Use a proxy
server for your LAN”. Then click [OK] to return to the “Connections” screen,
and click [OK] again to save your settings.
You should now be able to use Internet Explorer to browse the module as
required. However, to later restore your PC’s connection to your company
network, you may have to re-enable the use of a proxy server for your LAN.
There is no built-in error detection to prevent you from writing invalid values
to a configuration register. As such, if you inadvertently write an invalid value
to an internal register, you could cause the module to become inoperable
under certain conditions. If this happens, in order to regain control of the
module, the module can either be re-downloaded at the factory, or you can
try restoring the module to its initial configuration by following this procedure:
Procedure For Restoring any 9xxEN Module to its Initial Configuration
1. While module power is OFF, press and hold the front-panel toggle
switch in the default (DFT left) position.
2. While continuing to hold the toggle switch in the default position, apply
power to the module.
3. After a few seconds, the Status LED will begin to blink quickly and you
can release the default switch at this point. The module will continue to
boot itself as it normally does. That is, the green RUN LED will blink for
1-10 seconds as the unit acquires its address, then remain ON for
normal operation.
4. If the STATUS LED fails to blink rapidly after a few seconds and the
RUN LED just blinks for a few moments as it normally does, then
reinitializing the module has failed and you should try it again. This
time, make sure that the DFT switch is completely depressed and held
while powering the unit. Also make sure that you are pressing the DFT
toggle in the DFT direction (left), rather than the RST direction (right).
TROUBLE-
SHOOTING
Diagnostics Table
Trouble Browsing Your
Module?
Getting Out Of Trouble
So, your module’s “gone wild”,
follow this procedure to restore
it to its initial configuration and
regain control.

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17
TECHNICAL REFERENCE
•Safety Agency Approvals –CE, UL, & cUL listed, plus Class I; Division
2; Groups A, B, C, D approval.
•Modbus TCP/IP Protocol Support –Supports up to 10 master sockets
(maximum number is user-selectable) using port number 502 (Modbus
TCP/IP Default).
•Built-In Web Pages - Allows unit to optionally be configured, controlled,
calibrated, and monitored via a standard web browser over ethernet.
•Convenient “Wink” ID Mode Support –Blinks green RUN LED in wink
mode as a visual tool to help identify specific remote units on a network.
•Fully Independent w/ Direct I/O Connection –Self-contained with no
special bus couplers, power supply, or rack mount required to operate.
•Isolated Network Interface –Immune to noise & can operate over long
distances. Allows many modules to network together.
•Network Port is Transient Protected –Shielded RJ45 port includes
transient protection from ESD, EFT, and other transients.
•10Base-T and 100Base-TX Support –Integrated IEEE 802.3/802.3u
100Base-TX/10Base-T.
•Auto-Negotiated 10/100Mbps, Half or Full Duplex.
•Flexible Process Current Output (972EN) –Generates up to 6
process current signals in 3 ranges.
•Flexible DC Voltage Output (973EN) –Generates up to 6 DC voltage
signals in 3 ranges.
•Selected Ranges May Vary Channel-to-Channel –Multiple channels
may have different ranges configured.
•Precise High-Resolution D/A Conversion –Modules use high
resolution (12-bit), low noise, digital-to-analog conversion for high
accuracy and reliability.
•Nonvolatile Reprogrammable Memory –Allows the functionality of this
device to be reliably reprogrammed thousands of times.
•Fully Isolated –Output channels (as a group), network, and power are
all isolated from each other for safety and increased noise immunity.
•Plug-In Terminal Blocks & DIN-Rail Mount - Make mounting, removal,
and replacement easy.
•Operation/Diagnostic LED Indicators Aide Troubleshooting –Yellow
ACT LED indicates port activity (busy). Green LNK LED indicates link
(auto-negotiation complete and connection established). Green RUN
LED indicates power is ON or wink ID mode (blinking). Yellow ST LED
indicates module status.
•Internal Watchdog - A hardware watchdog timer is built into the
microcontroller that causes it to initiate a self reset if the controller ever
“locks up” or fails to return from an operation in a timely manner.
•Wide-Range DC-Power –Wide range diode-coupled for use with
redundant supplies, and/or battery back-up.
•Hardened For Harsh Environments - For protection from RFI, EMI,
ESD, EFT, & surges. Has low radiated emissions per CE requirements.
•Wide Ambient Operation –Reliable over a wide temperature range.
KEY FEATURES

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These transmitters will drive up to six analog current outputs (972EN), or six
analog voltage outputs (973EN), and provide an isolated 10/100 Ethernet
interface for configuration, monitoring, and control of the outputs. The
microcontroller completes the output transfer function according to the
output type & range per its embedded program, and sends output values to
two, 12-bit, quad-output DAC’s (Digital-to-Analog Converters). The
corresponding DAC output voltages are sent to individual voltage-to-current
converter circuits (972EN), or to non-inverting output amplifiers (973EN).
Outputs share a common return and are not isolated channel-to-channel.
Output configuration and calibration parameters are stored in non-volatile
memory integrated within the microcontroller. A dedicated Ethernet
controller handles Ethernet communication. The I/O terminals and the
Ethernet port terminals also include transient suppression. A wide input
switching regulator (isolated flyback) provides isolated power to the output
circuit and the Ethernet controller. A second switcher converts the 15V
output supply to a 5V logic supply. Refer to the simplified schematic shown
below to help gain a better understanding of the circuit.
HOW IT WORKS
8
5RJ45
2
RTN
OUT+
RTN
or
or
12-bit
DAC
12-bit
DAC
+3.3V
RUN STA
+5V
ACT
+15V
3.3V
LINK
15-36VDC
6
3
4
7
OUT+
+3.3V +3.3V
1
P
O
W
E
R
OUTPUTCHANNEL1OF6(Typical)
EARTH
GROUND
100
VOLTAGE
AMPLIFIER
OUTPUTCHANNEL6OF6
VOLTAGE
AMPLIFIER
OUTPUT/LOGIC
POWER
I/OLOGIC
POWER
RTC
TOGGLESWITCH
MICRO
CONTROLLER
MICRO
CONTROLLER
+3.3V
EARTH GROUND
+3.3V
EthernetPortIncludes
ESD Protection
DC+
GND
LRTN
V-TO-I
CONVERTER
V-TO-I
CONVERTER
-0.7V
+3.3V +3.3V
ISOLATED
FLYBACK
SWITCHER DC-
SWITCHER
ISOLATED INPUTPOWER
FLASH
(512Kx8)
SRAM
(512Kx8)
ETHERNET
CONTROLLER
ISOLATED ETHERNET

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19
Checksum
TCP FRAME
MODBUS FRAME
Transaction Identifier Modbus FrameLength FieldProtocol Identifier
DataAddress Function Code
Modbus Checksum
Not Included
TCP/IP is the foundation for the World Wide Web and refers to the
Transmission Control Protocol and Internet Protocol. TCP/IP allows blocks
of binary data to be exchanged between computers. The primary function of
TCP is to ensure that all packets of data are received correctly, while IP
makes sure that messages are correctly addressed and routed. Note that
the TCP/IP combination does not define what the data means or how the
data is to be interpreted, it is merely a transport protocol.
Modbus is an application protocol. It defines rules for organizing and
interpreting data and is essentially a messaging structure that is independent
of the underlying physical layer. It is freely available and accessible to
anyone, easy to understand, and widely supported by many manufacturers.
Modbus TCP/IP uses TCP/IP and Ethernet to carry the data of the Modbus
message structure between devices. That is, Modbus TCP/IP combines a
physical network (Ethernet), with a networking standard (TCP/IP), and a
standard method of representing data (Modbus). A Modbus TCP/IP
message is simply a Modbus communication encapsulated in an Ethernet
TCP/IP wrapper.
In practice, Modbus TCP embeds a Modbus data frame into a TCP frame,
without the Modbus checksum, as shown in the following diagram. The
Modbus checksum is not used, as the standard ethernet TCP/IP link layer
checksum methods are instead used to guaranty data integrity.
Note that the Modbus address field is referred to as the Unit Identifier in
Modbus TCP. In a typical slave application, the Unit ID is ignored and just
echoed back in the response.
The operation of the 972/973EN industrial Ethernet modules is similar to
Acromag’s 917/918MB Modbus modules. The operation over Ethernet is
essentially transparent to the Modbus register/command structure. If you
are already familiar with Modbus or with Acromag Series 900MB modules,
then you are already familiar with the operation of the 972/973EN modules.
A host is any device on any network. On TCP/IP networks, each host has
one or more unique IP addresses. This module connected to an ethernet
network is a host.
An IP Address is a unique identification number for any host (this module) on
any TCP/IP network (including the internet). The IP address is made up of
four octets (8 bits), each octet having a value between 0-255 (00H-FFH).
The IP address is comprised of two parts: the network address (first part)
and the host address (last part). The number of octets of the four total that
belong to the network address depend on the Class definition (see below).
ABOUT MODBUS
TCP/IP
You can find more information
on Modbus TCP/IP by visiting
our web site and down-loading
whitepaper 8500-765,
Introduction To Modbus
TCP/IP.
IP Addressing