Specifications

MBX Bridge Help
Cyberlogic Technologies Inc. - 19 -
Source
Device Slave Path Filter
Destination
Device Network Type Routing Timeout
1
1-64
*
0
Modbus Plus
MB.0.0.0.0
5000
1
65-128
*
0
Modbus Plus
2.MB-64.0.0.0
5000
1
129-192
*
0
Modbus Plus
3.MB-128.0.0.0
5000
1
193-256
*
0
Modbus Plus
4.MB-192.0.0.0
5000
To see how this routing works, we will examine the process by which the Modbus master
sends a message to the 984 controller at node address 20 on the Modbus Plus network.
In this example, we assume that the bridge’s Modbus slave device is configured so that
messages sent to Modbus address 1 use slave path 1, those sent to Modbus address 2
use slave path 2, and so on.
1. The host computer sends a message to node address 20.
2. The MBX Bridge receives the message on MBX device 1 over slave path number 20,
the same number as the destination node address value. This matches the Device
and Slave Path requirements for the first routing record. The Source Filter is an
asterisk, so all messages will pass that requirement.
3. The Bridge routes the message to its destination. The routing record specifies that it
should be sent to the PCI-85 designated MBX device 0. The Modbus node address of
the message is used as the first byte in the Modbus Plus routing array, with the
remaining bytes set to 0. This results in a routing of 20.0.0.0.0.
4. The message is delivered to its destination at Modbus Plus node address 20. The
message is processed and the reply is sent back to the MBX Bridge, which passes it
over to the host computer.
Modbus Plus to Modbus
This example assumes that we have a PCI-85 adapter card configured as MBX device 0
and a Serial MBX Master device configured as MBX Device 1.