Siemens Sinamics G120 CU240S DP - USS Process Data Channel (PZD)

Functions
5.11 Operation in fieldbus systems
Frequency inverter
Operating Instructions, 08.10. 2008, t.b.d.
159
5.11.1.4 USS process data channel (PZD)
Description
Process data (PZD) is exchanged continuously between the master and slave in this
message frame range. Depending on the direction of transfer, the process data channel
contains request data for the USS slave or response data to the USS master. The request
contains control words and setpoints for the slaves, while the response contains status
words and actual values for the master.
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Figure 5-17 USS process data channel
The number of PZD words in a USS message frame is defined by parameter P2012. The
first two words are:
● Control 1 (STW1) and main setpoint (HSW)
● Status word 1 (ZSW1) and main actual value (HIW)
If P2012 is greater than or the same as 4, the additional control word (STW2) is transferred
as the fourth PZD word (default setting).
The sources of all the other PZDs are defined with parameter P2019 for an RS 485 interface
and with P2016 for an RS 232 interface.