Siemens SED2-MODBUS2 Owner's manual

Technical Instructions
Document No. 155-767
February 25, 2009
Modbus RTU Interface Module for SED2
Siemens Industry, Inc.
Description The Modbus RTU Interface Module for SED2 enables serial communication
between a Modbus RTU and a SED2 Variable Frequency Drive (VFD).
Product Part Number SED2-MODBUS2
Contents •MicroGate II Interface module.
•Local cable for USS communication with SED2.
•Network cable for ModBus communication with Building Automation
controller.
•Installation documentation.
Required Tools Personal computer for configuring device prior to operation.
Configuration Kit (SED2-MODBUS2_KIT), containing:
•External Power Supply for the MicroGate II.
•9-pin (female) to 9-pin (female) Serial Null Modem Cable.
•Installation documentation.
NOTE: Both the Interface Module and the SED2 must be configured prior to
operation.
Figure 1.

Technical Instructions Modbus RTU Interface Module for SED2
Document Number 155-767
February 25, 2009
Page 2 Siemens Industry, Inc.
Warning/Caution Notations
WARNING: Personal injury/loss of life may occur if you do not
perform a procedure as specified.
CAUTION:
Equipment damage, or loss of data may occur if
you do not follow procedure as specified
Hardware Setup
Power Supply
Power may be supplied by either connecting the configuration kit power supply to one side of
the unit, or by providing regulated 6 to 28 Vdc power to pin 9 of the local serial port from the
SED2. See Figure 2.
WARNING:
Do not connect the external 9 Vdc power supply and pin 9
of the LOCAL cable at the same time.
Programming Switch The Programming (PRG) Switch on the Interface Module, should always be in the RUN
position (up) for normal operations and configuration.
The PRG position is used strictly for loading firmware at the factory.
The Interface Module comes with two serial ports. See Figure 2.
The LOCAL port is for connection to a SED2 and supports both RS232 and RS485 (2-wire
and ground) communications. The LOCAL port is also used for configuration and
programming of the Interface Module.
The NETWORK port is for connection to a network and supports RS485 (2-wire)
communications.
Figure 2. Interface Module Hardware.

Modbus RTU Interface Module for SED2 Technical Instructions
Document Number 155-767
February 25, 2009
Siemens Industry, Inc. Page 3
Hardware Setup, Continued
Figure 3. Three Wire
Network Cable.
The Interface Module is provided with two cables.
A three wire cable (Figure 3) connects the NETWORK port to a network. Because the
network connection type may vary among different installations, the cable ends are
stripped wires to provide maximum flexibility.
Figure 4. RS485 Network Cable.
Figure 5. Four Wire
Local Port Cable.
A four wire cable (Figure 5) connects the LOCAL port on the Interface Module to an
SED2. The cable ends in stripped wires to facilitate a connection to the SED2 drive
terminals shown below.
CAUTION:
SED2 drive power should be off while connecting
the wires to the drive terminals.
Figure 6. SED2 Drive Cable.
Figure 7. Cables Installed on Interface Module.

Technical Instructions Modbus RTU Interface Module for SED2
Document Number 155-767
February 25, 2009
Page 4 Siemens Industry, Inc.
Hardware Setup,
Continued
LED Indicators
Figure 8.
There are a total of three bi-color LED indicators on the Interface Module. See
Figure 8. The NET LED displays communications activity on the Network (Modbus)
port.
•The STAT LED displays the overall status of the Interface Module.
•The LCL LED displays communications activity on the Local (SED2) port.
During normal operations, the NET and LCL LEDs will quickly alternate red and green
flashes, making it look almost amber; this is normal.
Table 1. Interface Module General Status LED (Stat).
For this state: LED is: To indicate:
No power Off No power applied to the device.
Run Mode Flashing Green
(250 ms On, 250 ms Off) Interface Module is operating normally in RUN Mode.
Configuration Mode Flashing Green
(1.5 sec on, 1.5 sec Off) Interface Module is in CONFIGURATION Mode.
Fatal Error Flashing Yellow
(250 ms On, 250 ms Off)
Interface Module has
experienced a fatal error, and
has halted communication.
NOTE: If the Interface Module has been installed correctly, the STAT LED will be
flashing green, and the LCL LED will be alternating so fast between red and
green that it will appear to be glowing amber.
Table 2. Network Communication Activity LED (NET).
For this state: LED is: To indicate:
Received Data Red Data from the Modbus Network.
Transmit Data Green Data onto the Modbus Network.
Table 3. SED2 Communications Activity LED (LCL).
For this state: LED is: To indicate:
Received Data Red Data from the SED2.
Transmit Data Green Data to the SED2.

Modbus RTU Interface Module for SED2 Technical Instructions
Document Number 155-767
February 25, 2009
Siemens Industry, Inc. Page 5
Hardware Setup
Continued
Default Configuration
Table 4. Configuration Options.
Parameter Options Default
Protocol
Interface Module ASCII
Interface Module RTU
Interface Module
RTU
Interface
Module ID
1… 254 2
Baud Rate
1200 bps
4800 bps
9600 bps
9600 bps
19200 bps
38400 bps
57600 bps
115200 bps
9600 bps
Data Bits
7
8
8
Parity
None
Even
Odd
Even
Stop Bits
1
2
1
Changing the
Configuration The configuration stored in the Interface Module may be changed from the default
configuration by entering CONFIGURATION Mode.
1. Attach a configuration cable between the LOCAL port and a serial port on a
computer.
2. Start a terminal program, such as HyperTerminal, on the computer, and connect
using the following setting:
•Baud = 9600 bps
•Data bits = 8
•Parity = None
•Stop bits = 1
•Flow control = None
3. With the Programming Switch set to RUN, apply power to the Interface Module,
and press the ENTER key within five seconds of startup. See Figure 9.

Technical Instructions Modbus RTU Interface Module for SED2
Document Number 155-767
February 25, 2009
Page 6 Siemens Industry, Inc.
Changing the
Configuration,
Continued
Once the Interface Module is in CONFIGURATION Mode, it will send its current
configuration to the terminal program.
Figure 9. MicroGate II Configuration Display.
Table 5. Keyboard Navigation.
Use the UP and DOWN arrows, on the computer
keyboard, to navigate to the field you want to change.
Change values with the LEFT and RIGHT arrows.
Save Configuration Navigate to here and press ENTER to save changes.

Modbus RTU Interface Module for SED2 Technical Instructions
Document Number 155-767
February 25, 2009
Siemens Industry, Inc. Page 7
SED2 Parameter
Configuration The Interface Module communicates with the SED2 VFD using the USS protocol
and the following parameter configuration:
•USS address set to 0
•USS baud rate set to 19.2K
•Parity set to Even
•Number of data bits set to 8
Configure SED2 VFD parameters to communicate with the MicroGate II, per Table 3.
Table 6. SED2 Parameter Settings to Communicate with the MicroGate II.
SED2
Parameter Function Setting/Value
P0003 User Access Level 3 (Expert Level)
P0700[0] Command Source 5 if Starting/Stopping VFD from Modbus;
otherwise, DO NOT change.
P1000[0] Frequency Setpoint
Source 5 if Setting the Frequency from Modbus; otherwise, DO NOT change.
P2009[0] USS Normalization 0 (Disabled)
P2010[0] USS Baud Rate 7 (19.2K baud)
P2011[0] USS Address 0
P2014[0] USS telegram off time
0 to Disable the USS Watchdog timer.
100 or greater to enable the USS Watchdog
timer.
NOTE: Do not set to a value from 1 to 99.
P2041[0] Protocol Selection for
RS485 port 0 (USS Protocol)

Technical Instructions Modbus RTU Interface Module for SED2
Document Number 155-767
February 25, 2009
Page 8 Siemens Industry, Inc.
Watchdog Timer
Setup To enable an Interface Module Host Watchdog Function, the Interface Module Master
controls the first two holding Registers, WDOG TIME (40001) and WDOG ACTION
(40002).
When the Host Watchdog Function activates, the Interface Module does not receive any
further communications from the Master for a period of time determined by WDOG
TIME (40001). With WDOG ACTION (40002) set to 1, the SED2 stops on loss of
communications.
To activate the Interface Module Host Watchdog Function, set:
•WDOG TIME (40001) to the amount of time in milliseconds that must pass
with no further Interface Module communications.
•WDOG ACTION (40002) to 1so that the SED2 stops on loss of
communications with the Modbus master.
To deactivate the Interface Module Host Watchdog Function, set WDOG ACTION to 0.
SED2 Parameter 2014, USS Telegram Off Time, controls a Watchdog timer function for
the USS port.
•Once the Interface Module establishes communications with the SED2, if the
Interface Module stops communicating with the SED2, the SED2 automatically
enters the fault state with a F0070 fault number.
•Parameter P2014 specifies the timeout value for the USS Watchdog timer
function.
If P2014 is set to 0, the USS Watchdog timer is disabled. If P2014 is set to a non-zero
value, the USS Watchdog timer function is enabled and the timeout value is the P2014
non-zero value.
If using the USS Watchdog timer function with the Interface Module, set P2014 to a
value of 100 or greater so that accidental faults do not occur because of normal
communications delays between the Interface Module and the SED2.

Modbus RTU Interface Module for SED2 Technical Instructions
Document Number 155-767
February 25, 2009
Siemens Industry, Inc. Page 9
Verifying the
Installation
After all necessary connections have been made, power up the SED2 and the
Interface Module. Wait approximately five seconds.
NOTE: If the Interface Module has been installed correctly, the STAT LED will
be flashing green, and the LCL LED will be alternating so fast between
red and green that it will appear to be glowing amber.
Modbus Interface
Module with
Network as
Command Source
If not using the Modbus for commands, do not change P0700[0] and P1000[0].
Instead, verify communications by issuing a start command (from the source) and
checking the feedback on the Modbus master device to ensure that it reads proper
values in the appropriate Registers.
Modbus Interface
Module with
Network as
Command Source
1. To verify that the Interface Module and SED2 are set up correctly, set P0700[0]
and P1000[0] to a value of 5so that the SED2 can be controlled from the
Interface Module network.
2. From the Interface Module host, issue an Interface Module write, with of a value
of 8192 (2000h, or 50% of the maximum frequency) to the FREQ REF register
(40003 followed by a Modbus write with the value of 1 to the ENABLE register
(40004).
3. Write a value of 1 to the CMD START register to stop the drive again. The SED2
frequency can be changed at any time during this process by writing to the
FREQ REF register (40003).

Technical Instructions Modbus RTU Interface Module for SED2
Document Number 155-767
February 25, 2009
Page 10 Siemens Industry, Inc.
Interface Module
Registers
The following tables contain the lists of all Interface Module holding Registers available
on the Interface Module. The Interface Module host may write to Registers 40001
through 40023. All other Registers are read only.
There is a scaling factor included for some of the Registers. Because Modbus does not
represent floating point numbers, all floating point values in the drive are converted to
integer register values by applying a scaling (multiplication) factor. The scaling factors
are in the range of 10 to 1000.
For example: ACCEL TIME has a scaling factor of 100. If the SED2 contains a
value of 20.50, then the ACCEL TIME register will contain a value of 2050.
FREQ REF (40003) and FREQ ACTUAL (40063) are special case Registers. FREQ
REF contains the raw integer value passed in the HSW portion of a USS protocol
request to the SED2 drive. FREQ Actual contains the raw integer value passed in the
HIW portion of a USS protocol response from the SED2. Both Registers are scaled so
that a value of 4000th represents 100% of the actual frequency.
FREQ SCALED (40044) contains a scaled version of the HIW data, so that a value of
2000 in the register represents the value 4000h in the USS protocol response (and
100% of the maximum frequency).
STW and HSW refer to the 1st and 2nd control words, respectively, of PZD data
included in every poll sent from the Interface Module to the SED2 drive via the USS
protocol. ZSW and HIW refer to the 1st and 2nd status words, respectively, of PZD data
included in every poll response from the SED2 drive to the Interface Module via the USS
protocol. Registers mapped to PZD data are updated frequently.
All other parameters (except WDOG ACTION and WDOG TIME), which are handled
internally in the Interface Module, are mapped to parameters in the SED2 drive, and are
updated cyclically.
•Registers mapped to monitor parameters—
such as CURRENT or SPEED, whose values change automatically during
normal operation of the drive, without the intervention of an operator—are
updated at a rate of approximately once per second.
•Registers mapped to setup parameters—such as ACCEL TIME or FREQ
MAX, whose values typically change only via intervention by an operator—are
updated at a rate of approximately once every five seconds.