Configuring the fieldbus
6.2 Communication via RS485
Frequency inverters with Control Units CU230P-2 HVAC, CU230P-2 DP, CU230P-2 CAN
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Operating Instructions, 01/2011, FW 4.4, A5E02430659B AD
Telegram monitoring of the master
With your USS master, we recommend that the following times are monitored:
•
Response delay:
Response time of the slave to a request from the master
The response delay must be < 20 ms, but longer than the start
delay
•
Telegram runtime:
Transmission time of the response telegram sent from the slave
Telegram monitoring of the converter
The converter monitors the time between two requests of the master. Parameter p2040
defines the permissible time in ms. If a time p2040 ≠ 0 is exceeded, then the converter
interprets this as telegram failure and responds with fault F01910.
150% of the residual runtime is the guide value for the setting of p2040, i.e. the telegram
runtime without taking into account the character delay times.
For communication via USS, the converter checks bit 10 of the received control word 1. If the
bit is not set when the motor is switched on ("Operation"), then the converter responds with
fault F07220.
Summary of Contents for SINAMICS G120 CU230P-2
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