Appendix b – Hitachi L2002 User Manual

Page 243

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L200

2

Inverter

Appendix B

B–7

Data:

• A function command is set here.

• The data format used in the L200

2

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
L200

2

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)

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