Hitachi SJ200 Series - Manual (Page 221)

SJ200 Inverter
Appendix B
B–7
Data:
• A function command is set here.
• The data format used in the SJ200 series is corresponding to the Modbus data format
below.
Function code:
Specify a function you want to make the inverter execute. Function codes available to the
SJ200 series are listed below.
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).
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
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 Register 4 4 registers (in bytes)
0 5 h Write in Coil 1 1 coil (in bits)
0 6 h Write in Holding Register 1 1registers (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)