User`s manual

SH-300 User’s Manual Connection with PLC

Page 81 of 103

6.2.3. Here is an example of displaying and setting Register R1088

According to “the list of corresponding relationship between the address type and function

codes in Modbus Protocol” the address type of reading and writing holding register is “4X” ,The

holding register address is in the range of R0-R3839. Modbus address is in the range of 0-3839. the

corresponding Modbus data address of register R1088 is 1088.

When SH-300 read holding register the data format to be send from SH-300 and responded by

PLC is shown as following.

Query message Response message

Field Name Example(Hex) Field Name Example(Hex)

Device address - Device address -

Function code 04 Function code 04

40 Data Hi (Register R1088) -

No. of registers Hi 00 Data Lo (Register R1088) -

No. of registers Lo 01 CRC Lo -

CRC Lo - CRC Hi -

CRC Hi -

When SH-300 write holding register the data format to be send from SH-300 is shown as

following.

Query message

Field Name Example (Hex)

Device address 11

Function code 06

Set data Hi 00

Set data Lo 03

CRC Lo -

CRC Hi -

Response :The normal response is an echo of the query, returned after the register contents

have been written.

Note:

1. If the communication parameter is not correct. SH-300 will not communicate with PLC

normally.

2. If the data address you input is not in the range that is specified by user manual. SH-300 will

not communicate with PLC normally.

3. If PLC don’t support the address type you select (For example Delta PLC don’t support “3X”).

SH-300 will not communicate with PLC normally.