Configuring the fieldbus
6.2 Communication via RS485
Frequency inverters with Control Units CU230P-2 HVAC, CU230P-2 DP, CU230P-2 CAN
130
Operating Instructions, 01/2011, FW 4.4, A5E02430659B AD
6.2.2.8
USS process data channel (PZD)
Description
Process data (PZD) is exchanged between the master and slave in this telegram range.
Depending on the direction of transfer, the process data channel contains request data for
the slave or response data to the master. The request contains control words and setpoints
for the slaves, while the response contains status words and actual values for the master.
67:
+6:
67:
S
=6:
+,:
=6:
S
S
3='
3='
3='
3='
3='
3='
3='
3='
3='
3='
5HVSRQVH
WR866PDVWHU
5HTXHVW
WR866VODYH
Figure 6-9
Process data channel
The number of PZD words in a USS telegram is defined by parameter p2022. The first two
words are:
●
Control 1 (STW1, r0054) and main setpoint (HSW)
●
Status word 1 (ZSW1, r0052) and main actual value (HIW)
If P2022 is greater than or the same as 4, the additional control word (STW2, r0055) is
transferred as the fourth PZD word (default setting).
You define the sources of the PZD using parameter p2051.
For further information, please refer to the Parameter Manual.
6.2.2.9
Time-out and other errors
You require the telegram runtimes in order to set the telegram monitoring. The character
runtime is the basis of the telegram runtime:
Table 6- 27 Character runtime
Baud rate in bit/s
Transmission time per bit
Character run time (= 11 bits)
9600
104.170 µs
1.146 ms
19200
52.084 µs
0.573 ms
38400
26.042 µs
0.286 ms
115200
5.340 µs
0.059 ms
Summary of Contents for SINAMICS G120 CU230P-2
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