Hitachi WJ200-001L, Instruction Manual

Page: 342 / 680

B

7
Data:
 A function command is set here.
 The data format used in the X200
2
series is corresponding to the Modbus data
format below.
Name of Data Description
Coil Binary data that can be referenced and changed ( 1 bit long)
Holding Register 16-bit data that can be referenced and changed
Function code:
Specify a function you want to make the inverter execute. Function codes available to
the X200
2
series are listed below.
Function
Code
Function
Maximum data size
(bytes available
per message)
Maximum number of
data elements available
per message
0 1 h Read Coil Status 4 32 coils (in bits)
0 3 h Read Holding Resistor 32 16 registers (in bytes)
0 5 h Write in Coil 2 1 coil (in bits)
0 6 h Write in Holding Register 2 1 register (in bytes)
0 8 h Loopback Test
 
0 F h Write in Coils 4 32 coils (in bits)
1 0 h Write in Registers 32 16 registers (in bytes)
17
ｈ
Read/Write Holding Registor 32 16 registers (in bytes)
Error check:
Modbus-RTU uses CRC (Cyclic Redundancy Check) for error checking.
 The CRC code is 16-bit data that is generated for 8-bit blocks of arbitrary length.

The CRC code is generated by a generator polynomial CRC-16 (X16+ X15+ X2+ 1).
Header and trailer (silent interval):
Latency is the time between the reception of a query from the master and transmission
of a response from the inverter.
 3.5 characters (24 bits) are always required for latency time. If the latency time
shorter than 3.5 characters, the inverter returns no response.

The actual transmission latency time is the sum of silent interval (3.5 characters
long) + C078 (transmission latency time).