Siemens SINAMICS G120XA, Operating Instructions Manual

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6.2.3.7 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 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.
Advanced commissioning
6.2 Drive control
SINAMICS G120XA converter
Operating Instructions, 03/2019, FW V1.0, A5E44751205B AB
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