User Manual

Communication via RS485
5.4 Communication using Modbus RTU
Fieldbuses
136 Function Manual, 04/2018, FW V4.7 SP10, A5E34229197B AE
5.4.5
Acyclic communication via Modbus RTU
Acyclic communication or general parameter access is realized using the Modbus register
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 actual inverter 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. The error codes are described in the PROFIdrive profile.