User`s manual

MGate MB3000 User’s Manual Configuring the Modbus Gateway
4-10
SID Map Settings
Setting Value Notes
Virtual Slaves ID Range
(numeric range
from 1 to 254)
This specifies the range of IDs that will
be routed to the selected set of slave
devices. For example, you can specify
that IDs between 8 and 24 be routed to
the devices on Port 3. The ID 255 is
reserved for the gateway it's self
Slave ID Offset
(number between
-253 and 253)
This specifies the difference between the
virtual slave ID and the actual slave ID.
For example, if you want the virtual ID to
be 16 but the slave’s actual ID is 5, you
would set the offset to -10.
Slaves Channel IP
0.0.0.0
(or other 32-bit number)
If a Modbus RTU or ASCII master is
connected, this specifies the IP address of
a Modbus TCP slave.
ID Table Example
Suppose you were using the four-port MGate MB3480 to integrate two Modbus networks. You
want to connect two Modbus ASCII masters to Ports 2 and 4, which will need access to three
Modbus TCP slaves. You will also connect several Modbus ASCII slaves to Ports 1 and 3. Since
the Modbus ASCII slaves have fixed IDs that cannot be changed, you want the MGate to re-map
the IDs as follows:
Actual Slave ID Virtual Slave ID Protocol Location
2 10 ASCII MGate Port 1
3 11 ASCII MGate Port 1
4 12 ASCII MGate Port 1
4 20 ASCII MGate Port 3
5 21 ASCII MGate Port 3
6 22 ASCII MGate Port 3
2 2 TCP 192.168.3.125
7 7 TCP 192.168.3.125
1 1 TCP 192.168.3.111