Hitachi SJ-P1 Series - Modbus Function Codes

7-4
Chapter 7
About the Modbus TCP
7.2.4 Modbus function code
The Modbus function codes available with the
inverter are shown the followings.
■Function code definition
The data format available with the Modbus is
shown below.
■Data format
For information about the code number of coil and
holding register, refer to the inverter user's guide.
Also, the data scale of each holding register is
determined by the data resolution.
(Examples)
・ In the case of the parameter "[Ab110]:
Multispeed-0 setting, 1st-motor" (register
number: 2F4Eh) its data resolution is 0.01[Hz],
hence the data scale is 100 times. That is, if the
data is 50.00[Hz], it is expressed as 5000d.
・ In the case of the parameter "[bC110]:
Electronic thermal level setting, 1st-motor"
(register number: 339Ah) (register number:
2F4Eh) its data resolution is 0.1[A], hence the
data scale is 10 times. That is, if the data is
25.0[A], it is expressed as 250d.
・ In the case of the parameter "[Hb110]: Async.
Motor constant R1, 1st-motor" (register
number: 3B06h to 3B07h) its data resolution is
0.000001[ohm], hence the data scale is
1000000 times. That is, if the data is
0.149378[ohm] it is expressed as 149378d.
Code
Function
Maximum data bytes
that can be handled by
1 message
Maximum number of datas that can
be handled by 1 message
01h
Read Coils
4
32 coils (bit unit)
03h
Read holding registers
32
16 registers (2 byte length unit)
05h
Write single coil
2
Single coil (bit unit)
06h
Write single register
2
Single register (2 byte length unit)
08h
Diagnostics
－
－
0Fh
Write multiple coils
4
32coils (bit unit)
10h
Write multiple registers
32
16 registers (2 byte length unit)
17h
Read/Write multiple registers
32
16 registers (2 byte length unit)
Items
Description
Coil
Binary data (1 bit length) that can be read or written.
Holding
register
16-bit word data that can be read or written.