Modbus Communication; Overview - Siemens SINAMICS V90 Operating Instructions Manual

Control functions
7.7 Communicating with the PLC
Main step
③
Select the USS communication protocol by parameter
p29007.
④
Set the transmission baud rate by parameter p29009.
⑤
Set control mode for the drive.
⑥
Save the parameters and restart the drive.
⑦
Access the parameters via USS.
Note
The USS protocol communication libraries of S7-200, S7-200 SMART V1.0, and S7-1200 do
not support the communication with the SINAMICS V90 servo drive.
7.7.2

Modbus communication

7.7.2.1

Overview

The SINAMICS V90 servo drive can communicate with the PLC through an RS485 cable
with the standard Modbus communication protocol. There are two ways of sending a
message to a slave. One is unicast mode (addresses 1 to 31), where the master addresses
the slave directly; the other is broadcast mode (address 0), where the master addresses all
slaves. The broadcast mode cannot be used for an error request since all slaves cannot
respond at once.
208
Sub step/comment
p29007 = 0: no protocol
•
p29007 = 1: USS protocol
•
p29007 = 2: Modbus protocol
•
5: 4800 baud
•
6: 9600 baud
•
7: 19200 baud
•
8: 38400 baud
•
9: 57600 baud
•
10: 76800 baud
•
11: 93750 baud
•
12: 115200 baud
•
13: 187500 baud
•
For IPos control mode, you can change the following parame-
ters via USS:
p2617[0...7], p2618[0...7], p2572, p2573
•
For S control mode, you can change the following parameter
via USS:
p1001 to p1007
•
Ten monitor parameters can be read by USS:
r0020, r0021, r0026, r0027, r0031, r0032, r0034, r0807,
•
r2556, and r2521
Operating Instructions, 09/2016, A5E36037884-002
SINAMICS V90, SIMOTICS S-1FL6