Adding MODBUS TCP slaves

Regular MODBUS TCP addressing

When a single MODBUS TCP device has its own IP address on the network, then the IP address is self sufficient to identify that slave.

New MODBUS TCP slaves can be created by using one of the following patterns:

127.0.0.1
Create just one slave that will reply to requests received from any network interface.
192.168.10.100
Create just one slave that will only reply to requests received on the network interface whose IP address is 192.168.10.100.
10.23.6.2, 10.23.6.8
Create 2 slaves that will reply to requests received on network interfaces whose IP addresses are 10.23.6.2, and 10.23.6.8.
10.23.6.2-10.23.6.8
Create 9 slaves that will reply to requests received on network interfaces whose IP addresses are 10.23.6.2, 10.23.6.3, ..., 10.23.6.7 and 10.23.6.8.

Note: the comma can be replaced by a new line. White spaces following the comma are ignored.

Multiple slaves sharing the same IP address

When more than one MODBUS TCP device share the same IP address on the network, then the IP address alone is not sufficient to identify each slave. This is the case when, for example, the IP address is owned by a TCP/SERIAL gateway and the actual MODBUS slaves are using MODBUS RTU protocol.

Such MODBUS slaves must be identified by both an IP address and a slave number, and can be created by using one of the following patterns:

127.0.0.1(17)
Create juste one slave at IP address 127.0.0.1 (listen on all network interfaces) and slave number 17.
192.168.10.100(10-15)
Create 6 slaves sharing the same IP address (local network interface 192.168.10.100). Each slave is assigned a slave number ranging from 10 to 15 included.