
Configuring the fieldbus
6.2 Communication via RS485
Frequency inverters with Control Units CU230P-2 HVAC, CU230P-2 DP, CU230P-2 CAN
Operating Instructions, 01/2011, FW 4.4, A5E02430659B AD
121
Description
Telegrams with both a variable and fixed length can be used. This can be selected using
parameters p2022 and p2023 to define the length of the PZD and the PKW within the net
data.
STX
1 byte
LGE
1 byte
ADR
1 byte
PKW
8 bytes (4 words: PKE + IND + PWE1 + PWE2)
Net data
(example)
PZD
4 bytes (2 words: PZD1 + PZD2)
BCC
1 byte
Start delay
The start delay must be maintained before a new master telegram is started.
STX
The STX block is an ASCII character (0x02) and indicates the beginning of a message.
LGE
LGE specifies the number of bytes that following in the telegram. It is defined as the sum of
the following bytes
●
Net data
●
ADR
●
BCC
The actual overall telegram length is two bytes longer because STX and LGE are not
counted in LGE.
Содержание SINAMICS G120 CU230P-2
Страница 2: ......