5.3 Modbus RTU
5-37
Chap. 5 USING STANDARD RS-485
5.3.2.3 Writing multiple function codes
Query
1 byte 1 byte 2 bytes 2 bytes 1 byte 2 to 32 bytes 2 bytes
Station No. 16 Function code Write data size Byte count Write data Error check
Hi, Lo, Hi, Lo,…
Normal response
1 byte 1 byte 2 bytes 2 bytes 2 bytes
Station No. 16 Function code Write data size Error check
Setting "Query"
Broadcasts can be used if the address is "0". In this case, the broadcast request is processed by all
inverters and no response is returned.
FC = 16
Function codes are 2 bytes in length and composed of an identification code and a number.
For details on identification codes, refer to the table in Section 5.3.2.1. The length of read data fields
is fixed at 2 bytes.
The setting range is 1-16. If you set a value of 17 or more, an error response will be returned. The
byte count is 1 byte in length. The setting range is 2-32. Set the byte count to twice the size of the
write data. The first 2 bytes of write data should be set to a Lo code (function code requested by the
query), and subsequent data should be Hi codes set in ascending order (address +1, address +2, etc).
Interpreting "Normal response"
The returned function code and write data size values are the same as for the query.
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