6.3.5.7
Acyclic communication via Modbus RTU
Acyclic communication or general parameter access is realized using the Modbus registers
40601 … 40722.
Acyclic communication is controlled using 40601. 40602 contains the function code (always =
47 = 2F hex) and the number of the following user data. User data are contained in registers
40603 … 40722.
Overview of acyclic communication
Value in the register
Explanation
40601
40602
40603 … 40722
0
47
…
…
Write values for acyclic access
1
47
Request
length
[bytes]
Request data
Activate acyclic access
2
47
Response
length
[bytes]
Response data
Response for a successful request
2
47
0
Error code
Response for an erronous request
Error codes
1 hex: Invalid Length (invalid length)
2 hex: Invalid State (in the current converter state, this action is not permitted)
3 hex: Invalid function code (FC ≠ 2F hex)
4 hex: Response not ready (the response has still not been issued)
5 hex: Internal Error (general system error)
Incorrect access operations to parameters via data set 47 are logged in registers
40603 … 40722.
Advanced commissioning
6.3 Drive control
SINAMICS G120X converter
Operating Instructions, 06/2019, FW V1.01, A5E44751209B AC
253