Fuji Electric FRENIC-VG Series - Reading Function Codes

5.3 Modbus RTU
5-35
Chap. 5 USING STANDARD RS-485
5.3.2.1 Reading function codes
Query
1 byte 1 byte 2 bytes 2 bytes 2 bytes
Station No. 03 Function code Read data size (max. 99) Error check
Normal response
1 byte 1 byte 1 byte 2 to 198 bytes 2 bytes
Station No. 03 Byte count Read data size (max. 198) Error check
Hi, Lo, Hi, Lo, Hi, Lo,…
Setting "Query"
This request cannot be used with broadcasts. Station number "0" cannot be used.
FC = 03
Function codes are 2 bytes in length and composed of an identification code and a number (Ex.
"F40" = F + 40). The Hi side corresponds to identification codes F, E-, L. The Lo side corresponds
to the number. The setting data range is 0-9, 11 (F-L, U) on the Hi side, and 0-99 on the Lo side. For
example, the setting data for F20 is "0014h".
Setting
Identification
code
Name Setting
Identification
code
Name
0 F Basic function 30 E1 Terminal function 1
1 E Terminal function 31 H1 High level function 1
2 C Control function 32 H2 High level function 2
3 P Motor 1 function 33 H3 High level function 3
4 H High level function 34 H4 High level function 4
5 A Motor 2 function 35 H5 High level function 5
6 o Option function 36 A1 Motor 3 function
7 S Command/function data 37 o1 Option function 1
8 M Monitor data 38 o2 Option function 2
9 L Elevator function 39 U1 User function 1
11 U User function SF
41 M1 Monitor data function 1
42 M2 Monitor data function 2
The length of read data is 2 bytes. The setting range is 1-99 (words). Make sure to set read data so
that it does not exceed the upper limit offset 99 of the function code. Otherwise, an error response
will be returned.
Interpreting "Normal response"
The byte count data range is 2-198. A byte count is twice the size of read data (1-99) for a query.
In the response, read data is listed in the order of Hi bytes and then Lo bytes for each word of data,
and each word of data is listed in the order of the function code (address) requested with the query,
and then the address +1, +2, etc. Missing function codes (F09, etc.) will be returned as "0000".