Industrial
Electronic Devices
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User Manual
Modbus TCP Slave / Modbus Master
Document code: MN67508_ENG Revision 1.100 Page 22 of 28
Example 1:
If you want, from TCP network, write a data it the RTU
network on the device at:
Address 5;
Through Gateway WORD 100 (Address RTU);
Address TCP 1000.
In the above scenario:
Specify the type of data between:
Coil Status (bit in read write);
Input Status (bit in read);
Holding Register (word in read and write);
Input Register (word in read).
From the side of the MODBUS TCP:
Address of data to read.
From the side of the MODBUS RTU:
Address of the device to interrogate;
Address of data to read on device.
Note:
If the RTU slave responds with an exception, that exception code will be transmitted to the TCP Master. If the RTU slave does not
respond within the estimated time defined by the Timeout parameter, an exception response will be given on TCP side: error code $0B.
Modbus TCP
Master
Modbus TCP 10/100
HD67508
Modbus RTU up to 115200
Module Modbus RTU
Slave
Address 5
Request to the gateway, from the “holding
register” in address 1000
(step 1)
Request by the gateway, from the “holding register” in
address 100 to the device in address 5
(step 2)
Return to the gateway, from the variable
100 of the device in address 5
(step 3)
Return to the TCP Master, from the variable 100 of the
device in address 5
(step 4)
