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Communication format
This is the format for communication between the AD-8551R and a host (PLC, PC, etc.) with Modbus RTU.
If communication between the host (PLC,PC, etc.) and AD-8551R is not possible, send the contents of the following
example from the host and check the communication.
■
When writing to Coil
Operation details
Write 1 to Coil 00 2004 of the AD-8551R where device address is 01 (Rezero instruction to the weighing instrument).
Sent from the master
Field name
Example (Hexadecimal)
Description
Header
None
（
No communication for 3.5 characters
）
Device address
0x01
Function code
0x05
Start address(Upper)
0x07
0x07D3 = 2003
(Note that address for communication is 1 less.)
Start address(Lower)
0xD3
Conversion data(Upper)
0xFF
Conversion data(Lower)
0x00
Error check
0x7CB7
Trailer
None
（
No communication for 3.5 characters
）
Response from the device
Field name
Example (Hexadecimal)
Description
Header
None
（
No communication for 3.5 characters
）
Device address
0x01
Function code
0x05
Start address(Upper)
0x07
0x07D3 = 2003
(Note that address for communication)
Start address(Lower)
0xD3
Conversion data(Upper)
0xFF
Conversion data(Lower)
0x00
Error check
0x7CB7
Trailer
None
（
No communication for 3.5 characters
）
