Siemens SINAMICS V20 Series User Manual

Communicating with the PLC
6.1 USS communication
SINAMICS V20 Inverter
106 Operating Instructions, 07/2012, A5E03728167
The messages are always sent in the following format (half-duplex communication):
STX LGE
ADR BCC1. STX
……
n.
STX
LGE ADR BCC
1.
……
n.
BCCn.
6WDUWGHOD\ 6WDUWGHOD\5HVSRQVHGHOD\
WLPH
0DVWHUVHQGLQJ
6ODYHVHQGLQJ
1H[WPDVWHU
PHVVDJH
ELWGDWD
ELW ELW ELW
3HYHQ 6WRS6WDUW
● Response delay time: 20 ms
● Start delay time: depends on baud rate (minimum operation time for 2-character string:
0.12 ... 2.3 ms)
● Message transfer sequence:
– master polls slave 1, then slave 1 responds
– master polls slave 2, then slave 2 responds
● Fixed framing characters that can not be altered:
– 8 data bits
– 1 parity-even bit
– 1 stop bit
Abbreviation Significance Size Explanation
STX Start of text ASCII characters 02 hex
LGE Telegram length 1 byte Contains the telegram length
ADR Address 1 byte Contains the slave address and the
telegram type (binary coded)
1. ...... n. Net characters Each 1 byte Net data, contents are dependent
on the request
BCC Block check character 1 byte Data security characters
Request and response IDs
Request and response IDs are written in bits 12 to 15 of the PKW (parameter ID value) part
of USS telegram.
Request IDs (master → slave)
Response ID
Request ID Description
positive negative
0 No request 0 7 / 8
1 Request parameter value 1 / 2 7 / 8
2 Modify parameter value (word) 1 7 / 8
3 Modify parameter value (double word) 2 7 / 8
4 Request descriptive element 3 7 / 8
6 Request parameter value (array) 4 / 5 7 / 8

Siemens SINAMICS V20 Series Specifications

General

Brand	Siemens
Model	SINAMICS V20 Series
Category	DC Drives
Language	English