BRONKHORST FLOW-BUS User manual

Instruction manual
FLOW-BUS interface
for digital
Mass Flow / Pressure instruments
Doc. no.: 9.17.024K Date: 26-02-2010
ATTENTION
Please read this instruction manual carefully before installing and operating the instrument.
Not following the guidelines could result in personal injury and/or damage to the equipment.

BRONKHORST HIGH-TECH B.V.
9.17.024 Page 2
SCOPE OF THIS MANUAL
This manual covers the interface part of digital massflow / pressure instruments for gases and
/ or liquids. It describes the communication between the instrument and the operator according
to the specific (fieldbus) protocol.
More information can be found in other documents.
Multibus instruments have modular instruction manuals consisting of:
-General instructions digital Mass Flow / Pressure instruments
laboratory style / IN-FLOW (document nr. 9.17.022)
-General instructions CORI-FLOW (document nr. 9.17.031)
-Operation instructions digital instruments (document nr. 9.17.023)
-Fieldbus/interface description:

BRONKHORST HIGH-TECH B.V.
9.17.024 Page 3
Short form start-up
Procedure:
1Connect instrument to the bus
cablecable
Y-adapter
7.03.319
cable
cable RJ45 toM12
beginterminator
7.03.297
Y-adapter
7.03.241
Y-adapter
7.03.319 Y-adapter 7.03.319
endterminator
7.03.321
Y-adapter
7.03.319
patchcable
Y-adapter
7.03.241
patchcable
Y-adapter
7.03.241
Y-adapter
7.03.241
patchcable
Y-adapter
7.03.241
beginterminator
7.03.297
patchcable
endterminator
7.03.298
Y-adapter
7.03.241
endterminator
7.03.321
Y-adapter
7.03.319
beginterminator
7.03.297
Y-adapter
7.03.241
Y-adapter
7.03.241
endterminator
7.03.298
beginterminator
7.03.297
Y-adapter
7.03.241
patchcable cable RJ45 to M12

BRONKHORST HIGH-TECH B.V.
9.17.024 Page 4
cable
endterminator
7.03.321
Y-adapter
7.03.319
Y-adapter
7.03.319
Y-adapter
7.03.319
cable cable
Y-adapter
7.03.241
beginterminator
7.03.297
cable RJ45 to M12
Y-adapter
7.03.319
cable
Y-adapter
7.03.319
Y-adapter
7.03.241
cable RJ45 to M12
Y-adapter
7.03.319
cable
cable RJ45 to M12
cable
Y-adapter
7.03.319 Y-adapter 7.03.319
power isolator
1.09.239
Y-adapter
7.03.241
beginterminator
7.03.297
endterminator
7.03.298
Y-adapter
7.03.241
patchcable
Y-adapter
7.03.241
patchcable patchcable patchcable
Y-adapter
7.03.241 Y-adapter
7.03.241
patchcable
patchcablepatchcable
Y-adapter
7.03.241
patchcable
Y-adapter
7.03.241
Y-adapter
7.03.241
Y-adapter
7.03.241
patchcable
Y-adapter
7.03.241
power isolator
7.03.350

BRONKHORST HIGH-TECH B.V.
9.17.024 Page 5
endterminator
7.03.321
Y-adapter
7.03.319
Bronkho rst
®
HIGH-TECH
beginterminator
7.03.297
endterminator
7.03.298 endterminator
7.03.298
Y-adapter
7.03.241 Y-adapter 7.03.241 Y-adapter 7.03.241
beginterminator
7.03.297
Y-adapter
7.03.241
Y-adapter
7.03.241
patchcable patchcable patchcable
Bronkhorst
®
HIGH-TECH
Bronkho rst
®
HIGH-TECH
Bronkhorst
®
HIGH-TECH
Y-adapter
7.03.319
Incorrect Correct
Y-adapter
7.03.319
endterminator
7.03.321
Y-adapter
7.03.319
beginterminator
7.03.297
Y-adapter
7.03.241
Incorrect Correct
The last instrument on the bus needs a bus-end-termination connector (black).
The first module on the bus (either an E-7000 module for digital instruments or a FLOW-BUS interface
module to a PC) needs a bus begin – terminator (red).

BRONKHORST HIGH-TECH B.V.
9.17.024 Page 6
2 Make instrument operational on the bus
(give it a FLOW-BUS node-address)
If rotary switches are present on the side of the instrument, please see paragraph 2.6.4.
Complete FLOW-BUS systems are already factory configured and tested and will be directly operational on
the bus. However, changes in the system or adding new modules could need new (free) addresses on the
FLOW-BUS.
Watch the LED’s on top of the instrument when the instrument powers-up.
If the green LED is burning continuously and the red LED is off, everything is o.k. the instrument is
operational on the bus.
If the red LED is blinking slowly, the FLOW-BUS address is already occupied. In that case: press the micro
push-button and release it after 2 seconds. Now the instrument is operational on the bus (pressing the push-
button for 1 to 4 seconds will activate the auto install function, the instrument will install itself to a free node-
address).
3 Make link to operator module
(search module on the bus with the operator).
You can search for this instrument, looking for type and serial number.
a With E-7000 module for digital instruments:
Go to the FLOW-BUS menu and select “OPERATE INSTR.”.
Use <- or -> keys to search the bus for the wanted instrument.
Instruments can be identified by their serial number. Also both LED’s on the instrument will blink turn by
turn (wink) for some seconds.
When found, press middle-key (enter) to make connection for operation.
b With PC-software application:
When you use FLOWDDE or FLOWBUS.DLL (for Windows applications) all
modules connected to FLOW-BUS will be recognised automatically. They will be assigned to a channel
for operation. (see FLOW-DDE configuration menu)
Other programs will have to get procedures for reading identification of instruments. For details, see
FLOW-BUS software documentation.
Send a setpoint to the instrument and check the measured value
Let the instrument warm-up for 30 minutes for best accuracy
Your Mass Flow Meter/Controller is now ready for operation.

BRONKHORST HIGH-TECH B.V.
9.17.024 Page 7
Table of contents
1Changing parameters via FLOW-BUS.......................................................................................................................8
2FLOW-BUS.................................................................................................................................................................9
2.1 General................................................................................................................................................................9
2.2 Technical information ..........................................................................................................................................9
2.3 Cables ...............................................................................................................................................................10
2.4 Termination .......................................................................................................................................................10
2.5 Power supply.....................................................................................................................................................11
2.6 Installation .........................................................................................................................................................11
2.6.1 Automatic installation to FLOW-BUS.........................................................................................................11
2.6.2 Remote installation to FLOW-BUS ............................................................................................................11
2.6.3 Install to bus on a pre-defined node-address or re-address instrument on the bus..................................12
2.6.4 Install to bus via rotary switches on the side of the instrument (if present)...............................................12
2.7 Security and flexibility........................................................................................................................................13
3FLOW-BUS system operation with computer...........................................................................................................14
3.1 Communication with FLOW-BUS DDE server..................................................................................................14
3.2 Communication with FLOW-BUS directly through DLL ....................................................................................14
3.3 Communication with interface directly through RS232.....................................................................................14
4FLOW-BUS connector..............................................................................................................................................15
TROUBLESHOOTING.....................................................................................................................................................16

BRONKHORST HIGH-TECH B.V.
9.17.024 Page 8
1 Changing parameters via FLOW-BUS
For security reasons all important instrument settings can only be changed after entering a
password (using E-7000 readout/control modules) or after sending a security-parameter (using
PC-software programs).
For operation of instruments there is always free access to the parameters (e.g. setpoint,
control mode, setpoint slope, changing fluid).
Changing of settings however, is secured (e.g. calibration parameters, input + output
adjustments, identification, FLOW-BUS network settings).
When using Bronkhorst High-Tech Electronics, like E-7000 systems, changing of parameter
settings at digital instruments is possible via the menu.
However, when changing of parameter settings via other (self-made) software running on
computers using RS232 and/or FLOW-BUS DLL and/or FLOWDDE is wanted, for safety
reasons setting of special initialisation parameters is needed first.
For changing secured parameter values by means of a PC-software program contact
Bronkhorst High-Tech B.V.
Nijverheidsstraat 1a
7261 AK Ruurlo
The Netherlands
tel: [phone]
fax: [phone]
mail: [e-mail]

BRONKHORST HIGH-TECH B.V.
9.17.024 Page 9
FLOW-BUS
IN/OUT
3
1
7.03.297
BEGIN TERMINATOR
7.03.241
MODULAR Y-ADAPTER
USERTAG AIR
10.00 ln/min
3
1.09.240
END TERMINATOR
EL-FLOW
mass flow meter/controller
FLOW-BUS
CE Ruurl o-Holland
EL-FLOW
mass flow meter/controller
FLOW-BUS
CE Ruurlo-Holland
EL-FLOW
massf low meter/controller
FLOW-BUS
CE Ruurl o-Holland
EL-FLOW
massflow meter/controller
FLOW-BUS
CE Ruurlo-Holl and
7.03.299
RJ45 Multi-port adaptor 7.03.299 RJ45 Multi-port adaptor
EL-FLOW
mass flow meter/controller
FLOW-BUS
CE Ruurlo-Holland
EL-FLOW
massf low meter/controller
FLOW-BUS
CE Ruurlo-Holland
EL-FLOW
massflowmeter/controller
FLOW-BUS
CE Ruurlo-Holland
EL-FLOW
mass flow meter/controller
FLOW-BUS
CE Ruurlo-Holland
Node 1
Node 2
Node 3
Node 4
Node 5
Node 6
Node 7
Node 8
Node 9
Node 10
PowerIsolator
1.09.239
RS232
2 FLOW-BUS
2.1 General
FLOW-BUS is a 3-wire, RS485-based fieldbus communication system for parameter value exchange between
digital BRONKHORST HIGH-TECH B.V. products.
In this system each instrument/device is equipped with a micro-controller for its own dedicated task but also for
exchanging parameter value information with other instruments/devices connected to the same FLOW-BUS
system.
2.2 Technical information
FLOW-BUS systems may have a minimum of 2 and a maximum of 126 connections.
The maximum length for datalines between the first and the last connection may be up to approx. 600 meters.
Longer distances are only possible in combination with special bus-repeater modules.
Each instrument/device connection T-part (stub) must be kept as short as possible (max. cable length 0.5
meter!).
The baudrate used to transport messages is 187.5 Kbaud.
FLOW-BUS is a multi-master network with a token-ring architecture.

BRONKHORST HIGH-TECH B.V.
9.17.024 Page 10
2.3 Cables
For connecting instruments to the FLOW-BUS you need shielded cables with at least 3 wires (for data only).
Recommended are twisted wire cables for RS485-communications with 100 or 120 Ohm impedance.
All Bronkhorst High-Tech FLOW-BUS cables have also integrated power-supply wires.
For the use in the EL-FLOW range (non IP-65) it is best to use Shielded (+Foiled) Twisted Pair patch-cables
with RJ45 modular jack connectors (8-pins for data and power-supply connections).
For the use in for example the IN-FLOW range or CORI-FLOW range (IP-65 applications) it is best to use
DeviceNet Drop cables assembled on both sides with male connector M12 – female connector M12 (5-pins for
data and power-supply connections).
In case of powering instruments or transporting data over longer distances Bronkhorst High-Tech offers also
special RS485 FLOW-BUS datacable, with lower voltage-drop.
Bronkhorst High-Tech can advise you when to use this special cable, but for most cases the standard
patch-cables will do well.
If more cables are used in one system, they have to be connected as a daisy-chain. This means that the
total FLOW-BUS system has only one begin and one end.
For connecting instruments to the bus, Bronkhorst High-Tech offers special drop-cables which enable you
to build a daisy chained network of FLOW-BUS modules.
2.4 Termination
For best quality of data transfer FLOW-BUS should be terminated correctly.
Termination can be performed with special termination-connectors, offered by Bronkhorst High-Tech B.V.
At the begin of each FLOW-BUS system there always must be a resistor network as showed above.
This begin-terminator needs to be part of your system. Bronkhorst High-Tech offers special begin-termination
connectors with the resistor network.
This handles correct termination but also gives a defined voltage on the RS485-A and -B line for even more
reliability of the FLOW-BUS system.
Bronkhorst High-Tech advises always to use a termination resistor at the end of the bus in your system .
This end-terminator is also offered by Bronkhorst High-Tech and handles correct termination for the
FLOW-BUS.
Black
End
termination
Begin
termination
Red 0Vdc
Connected
modules
0Vdc
Power
supply
RS485-A
RS485-B
RS485-A
RS485-B
FLOWBUS

BRONKHORST HIGH-TECH B.V.
9.17.024 Page 11
2.5 Power supply
Bronkhorst High-Tech uses FLOW-BUS cables with extra wires inside for +15 Vdc/+24 Vdc and 0 Vdc in
order to handle power supply and communication with the same cable.
Because RS485-cabling needs a daisy-chain connection and power-lines prefer a star-point connection, we
came to a compromise of both in the FLOW-BUS cabling.
Bronkhorst High-Tech can advise you how to power your FLOW-BUS system.
It is the best to keep the power-lines as short as possible, so local power-supply is preferred.
This of course, depends on your demands of building-up your system.
A rule of thumb:
Using standard power-supplies from Bronkhorst High-Tech B.V. and Shielded Twisted Pair patch-cable
with RJ45 connectors for non IP65 applications and DeviceNet cables with circular M12 connectors for IP65
applications:
A cluster of 4 digital controllers can be powered locally from a distance approx. <= 6.5 meters from the
power-supply.
Powering more instruments will reduce the distance allowed to the supply-unit in linear relationship.
2.6 Installation
All modules in a FLOW-BUS system must have their own address.
FLOW-BUS systems will not function properly when there are more modules on the same address.
To avoid this, modules will do a check before getting operational on their bus-address and give a message
when this address is occupied.
If you receive a complete FLOW-BUS system from Bronkhorst High-Tech all modules have been installed
to the bus already (in one system).
Each time you power-up your system afterwards, the modules will start-up on the same address on the bus,
because these settings are stored in their non-volatile memory.
So if you receive a new system, normally you only have to connect the cables and switch on the power.
If a new module has to be connected to a bus system, it needs a free address. Normally this will be the first free
address counted from address 3.
Address 0 is reserved for the start-up procedure. Address 1 is reserved for an interface module to (personal)
computers and address 2 has been reserved for operation modules like E-7000.
There are four ways to add a new module to your bus system:
2.6.1 Automatic installation to FLOW-BUS
Most FLOW-BUS modules have the facility to install themselves automatically on the bus. This means that they
are able to find the first free node-address counted from 3 and connect themselves to the bus. This action can be
started by means of a manual interface on the module. Directly afterwards the new module will be part of the
FLOW-BUS system. See manual 9.17.023.
Note: make sure to install only one new module at the same time.
2.6.2 Remote installation to FLOW-BUS
Some FLOW-BUS modules have to be installed on the bus by means of another FLOW-BUS module or a
(personal) computer. This can be done as follows:
- By means of the micro-switch on the instrument. See instruction manual 9.17.023.
- With a Readout/Control module, series E-7000/E-7001 or with a software program on the PC this new
module can be searched.
- The Readout/Control module or PC-program will find the first free node-address counted from
address 3 (3 is first free address).
- This free address number will be send to the new module, which should become active on this
address.

BRONKHORST HIGH-TECH B.V.
9.17.024 Page 12
- After a reset command, also send by the Readout/Control module or PC-program, the new module will
be operational on the FLOW-BUS system.
Note: make sure to install only one new module at the same time.
2.6.3 Install to bus on a pre-defined node-address or re-address instrument on the bus
In some applications it is necessary to put FLOW-BUS devices on pre-defined addresses because of the
application software expecting this device on this address (e.g. PLC-applications). This can be done as follows:
(Install new module to the bus as described in the previous paragraphs.)
- By means of the micro-switch on the instrument. See instruction manual 9.17.023.
- By means of the special menu in an E-7000 module for digital instruments it is possible to (re-)
address instruments on the bus.
- Go to the specific menu part and read the PNA (Primary Node Address) number.
- Fill-in the address you want the instrument to have on the bus.
- The E-7000 module will check if this address is already occupied by another instrument. If so,
you could remove the other one and try again, or enter another address.
- The module will restart and will get its new address from that moment on.
Note 1:
Because it is not allowed in a FLOW-BUS system to have 2 devices on the same node-address, at (re)start of the
instrument there will also be a check performed if its node-address (in memory) is already occupied by another
device. If so, the red LED will blink slowly. At that moment the module is not operational on the bus. You first have
to re-install it.
The easiest way to do this is to press the micro push-button on top of the instrument until the green LED starts
blinking fast. After releasing the button the instrument will install itself on the bus automatically on a free address.
When the green LED is burning continuously, the instrument is operational.
Note 2:
If you take one or more modules out of your system, or if one or more modules do not get power, be careful
installing new modules, or changing the configuration.
This situation may occur if you take modules out for service. If you don’t change the configuration, you can
replace your serviced instrument/module in your system without any problem.
Mostly new modules will get the first free address, counted from address 3 (3 will be the first). This could be an
address which should not be occupied (e.g. from a module which has been taken-out for service). In that case
install the new module and re-address it as described, to avoid FLOW-BUS communication problems.
Note 3:
When connecting an instrument/module to the FLOW-BUS, make sure that the instrument/module is in power-off
mode.
After connection to the bus you can switch power on.
At power-up there will be a check to avoid the situation of two modules on the same bus address.
This is important for error-free bus-communication.
2.6.4 Install to bus via rotary switches on the side of the instrument (if present).
On the side of the instrument are rotary switches placed and a label
with the explanation of the switches. Make sure to use a screwdriver
which is suited for the switches.
The switches have the following function:
NODE ADDRESS (00 – 99)
With the NODE ADDRESS switch, the instruments address can be set. The MSD is the high part of the decimal
number and the LSD the low part. For instance address 25 means MSD on 2 and LSD on 5.
The default switch position is 00. In this position the address is software programmable.

BRONKHORST HIGH-TECH B.V.
9.17.024 Page 13
The default software programmable address is 3.
During instrument initialisation, the node address switches are read. If the switches specify a valid FLOW-BUS
address, i.e. a value from 3 to 99, this value is used.
If the specified address differs from the value stored in the instrument, the new address is saved in memory.
If the switches specify an invalid FLOW-BUS address, i.e. a value of 1 or 2, the value stored in the instrument’s
memory will be used as the address.
2.7 Security and flexibility
FLOW-BUS systems are designed to transport data as quickly and reliable as possible. There are integrated
mechanisms for checking, retry- and error- handling. Modules can be removed from the FLOW-BUS temporarily
(e.g. for service) and can be replaced or re-installed later.
New modules will be recognised automatically by other modules in the system.
FLOW-BUS systems can consist of at least 2 or maximum 126 Bronkhorst High-Tech products.

BRONKHORST HIGH-TECH B.V.
9.17.024 Page 14
3 FLOW-BUS system operation with computer
There are several options to do this.
First see that the chosen hardware is able to communicate with the FLOW-BUS system and that this can be
done with a sufficient velocity of parameter transfer for your application.
3.1 Communication with FLOW-BUS DDE server
Together with a client-application, either self-made or with a SCADA-program from 3rd-parties.
Examples: Genesis, Fix-MMI, Lotus Measure, Paragon, Wizcon, LabView, Intouch.
This option is far most convenient, less costful and most user friendly.
The FLOW-BUS DDE server also offers a lot of test facilities and user adjustable settings for efficient
communication with devices connected to the FLOW-BUS.
Programming examples are available for making applications in: Visual Basic, LabView and Excel.
Advantage:
Very powerful, fast communication, no special knowledge needed from bus-protocol and bus-system,
supported by BHT
Disadvantage:
not really, depends on demands of user:
can be used under Windows 95 and higher and Windows NT4.0 and Windows2000 only
large systems with need of very high update rates of data
(within < 1 sec.) is not possible
3.2 Communication with FLOW-BUS directly through DLL
Part of this FLOW-BUS software is a 32-bit DLL (for Windows95 and higher, Windows NT 4.0 and
Windows2000).
You may call the functions in this library directly to communicate with devices on the FLOW-BUS.
Further documentation may be ordered at your local sales representative.
Programming examples are available for making applications in Visual Basic and LabView.
Advantage:
powerful routines available for fast communication, less overhead, low processor load
Disadvantage:
knowledge needed from FLOW-BUS system about parameters, processes, nodes etc., complex
software structure, not suited for quickly building an application
3.3 Communication with interface directly through RS232
Mostly used by PLC-equipment or special PC-applications (e.g. Hyperterminal).
You have to write your own communication routines for operating the FLOW-BUS system by host computer.
The protocol for the communication between the modules is described in a PDF-file doc.nr. 9.17.027.
For an RS232-interface module messages will be send by means of ASCII-strings (or binary).
Advantage:
simple, straight forward, less overhead
Disadvantage:
knowledge needed from FLOW-BUS system about parameters, processes, nodes etc.

BRONKHORST HIGH-TECH B.V.
9.17.024 Page 15
18
4 FLOW-BUS connector
The shielded RJ45 modular jack connector (for non IP65 applications) has the following pin configuration:
Pinnumber Description
1
2
3
4
5
6
7
8
+ 15 Vdc/+ 24 Vdc supply
0 V
Shield
0 V
+ 15 Vdc/+ 24 Vdc supply
0 V
RS485 – B
RS485 – A
The chassis M12 circular connector (for IP65 applications) has the following pin configuration:
Pinnumber Description
1
2
3
4
5
Shield
+ 15 Vdc/+ 24 Vdc supply
0V
RS485 – A
RS485 – B
4
2
3
5
1
A
-
coded

BRONKHORST HIGH-TECH B.V.
9.17.024 Page 16
TROUBLESHOOTING
Symptom Possible cause Action
No output signal on FLOW-BUS
interface Bad communication with FLOW-BUS Check communication e.g. with local readout module or PC-test
program
No or slow response to setpoint
changes Slope value could be set too high (ramp function for setpoint signal) Check and/or change slope value with readout module or PC-software
program
Control mode/setpoint source for
instrument could point to a different
setpoint source
Check if correct control
mode/setpoint source is selected for
the instrument
Other instrument (or PC) connected
to FLOW-BUS could change the
setpoint
Make sure who is in charge to
change setpoints
Polynomial factors could be wrong Check if right fluid has been
selected and check polynomial
factors A..D with those on your
calibration certificate
Inaccuracy of measurement Wrong fluid (and thus calibration
settings) could be selected (up to 8
fluids possible)
Check if correct fluid is selected for
this instrument
Check if powering of instrument is
done correctly
Analog output range is too low/high Wrong output range could be selected Check if wanted output range
(analog) is selected
No/bad connection to FLOW-BUS Wrong cable used
Check cabling
Bad termination of RS485 bus-line Check bus termination
Other module(s) on the bus could
cause trouble Check correct functioning from other module(s) on the bus (PC-programs
with interface modules included)
No communication possible with PC-
software program Interface settings could be wrong Check settings e.g. for RS232 (COM-port and baudrate)
Interface has bad connection to
FLOW-BUS Check cabling of interface
Red or green LED’s are blinking on
top of the instrument Instrument is in a special operation mode or is indicating some kind of
error/warning
See manual 9.17.023 for more
details
No/bad reaction to manual
instructions by means of micro push-
button switch on top
Some actions can only be used under
special conditions See manual 9.17.023 for more details
Master-slave controlling doesn’t
function well Connection to master signal could be lost Check if master output is given correctly
Settings for this special controlling
mode could be wrong Check if settings are correct (control mode, slave-factor)
Controller doesn’t function as wanted Settings for controller are for other
behaviour than you want Under certain conditions you could run an auto-tune for controller
optimisation.
(see manual 9.17.023)
Change reponse factor settings for
controller (see manual of
readout/control module or
PC-software)
Other troubles One or more parameter settings could
be wrong Get back original factory settings by means of micro push-button on top
(see manual 9.17.023)
Contact sales representative for
assistance if the above doesn’t help