Modbus Communication - Modbus Tcp - ICPDAS GW-7238D User Manual

Or
Without have to control the Modbus register 42009 (Dec), just enable
Auto transmission function in J1939 configuration area as below, and
upload to GW-7238D.
Figure 5-13: J1939 Auto Transmission function screen
5.4 Modbus Communication – Modbus TCP
Set J1939 output data
Using the Modbus command as below:
FC16 Write multiple registers (4xxxx) for AO
[Request] (Request by Modbus master device)
Byte 0-1:
Byte 2-3:
Byte 4-5:
Byte 7:
Byte 8:
Byte 9-10:
Byte 11-12:
Byte 13:
Byte 14-(B+13): Register values
[Response] (Response from the GW-7238D)
Byte 0-1:
Byte 2-3:
Byte 4-5:
GW-7238D J1939 to MBTCP Server / MBRTU Slave Gateway User's Manual (Ver.1.0, Nov. 2011) --- 47
Transaction Identifier (Usually zero when making a
request)
Protocol Identifier (Protocol number. Must be zero)
Length (Number of following bytes - upper / lower
byte)
Net ID (Station number)
FC=10 (Hex)
Reference number
Word count
Byte count (B=2 x word count)
Transaction Identifier (Usually zero when making a
request)
Protocol Identifier (Protocol number. Must be zero)
Length (Number of following bytes - upper / lower
byte)