Hitachi CONVENTION 14 instruction manual B 7

Data:
xA function command is set here.
xThe data format used in the X200 series is corresponding to the Modbus data format
below.
Nameof 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
Functioncode:
Specify a function you want to make the inverter execute. Function codes available to
the X200 series are listed below.
FunctionCode Function
Maximumdata size
(bytesavailable
permessage)
Maximumnumber of
dataelements available
permessage
0 1 h Read Coil Status 4 32 coils (in bits)
0 3 h Read Holding Resistor 4 4 registers (in bytes)
0 5 h Write in Coil 1 1 coil (in bits)
0 6 h Write in Holding Register 1 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 4 4 registers (in bytes)
Errorcheck:
Modbus-RTU uses CRC (Cyclic Redundancy Check) for error checking.
xThe CRC code is 16-bit data that is generated for 8-bit blocks of arbitrary length.
xThe CRC code is generated by a generator polynomial CRC-16 (X16+ X15+ X2+ 1).
Headerand trailer (silent interval):
Latency is the time between the reception of a query from the master and transmission
of a response from the inverter.
x3.5 characters (24 bits) are always required for latency time. If the latency time
shorter than 3.5 characters, the inverter returns no response.
xThe actual transmission latency time is the sum of silent interval (3.5 characters
long) + C078 (transmission latency time).
B7
Appendix B
B 7
Appendix B