Schneider Electric Modbus Plus Network Bridge Multiplexer none User Manual

Page 47

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Configuring the Modbus Models

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V Entry 02 is an example of routing through a Bridge Plus to a

programmable controller at node address 14 on a second network.

Finding a match for Modbus address 182, the BM85 applies the

routing path 20, 14, 0, 0, 0 to the message. It will be sent to node

20 on the current Modbus Plus network, a Bridge Plus. It will be

routed through the bridge to node 14 on the second network.

V Entry 03 shows how the type of device at the destination can

determine the routing of a message. Finding a match for Modbus

address 27, the BM85 applies the routing path 20, 22, 5, 0, 0 to the

message. The message is sent to node 20 on the current network,

a Bridge Plus. The message is routed through the bridge to node

22 on the next network. The type of device at node 22 determines

how further routing is applied. If node 22 is another Bridge Plus,

the message is routed to node 5 on a third network. āIf node 22 is

an SA85 or SM85 Network Adapter, the message is accepted by the

adapter and posted to application task 5 running in the adapter.

V Entry 04 shows routing to a single slave device on another port of

the same BM85. Finding a match for Modbus address 33, the

BM85 will apply the routing path 0, 3, 0, 0, 0 to the message. The

zero in the first byte specifies internal routing to another Modbus

port. The second byte specifies port 3. Port 3 must have only a

single slave device connected, as the remaining bytes are zeros.

V Entry 05 shows routing to a networked slave device on another

port of the same BM85. If the Modbus message contains an

address of 125, the routing path 0, 4, 99, 0, 0 is applied. The zero

in the first byte specifies internal routing to another Modbus port.

The second byte specifies port 4. The third byte specifies slave

device address 99 on the network at that port. The remaining

bytes must contain zeros.

If a Match is Not Found

If an address match is not found in the table, the Modbus address in the

message will be converted by the BM85 into a routing path using the

methods described below. The resulting path can be either to the

Modbus Plus network, or to a single slave device connected to another

Modbus port of the Bridge Multiplexer.

V Address Range 1 ... 64 If the message contains an address in the

range 1 ... 64 decimal, it will be sent to the Modbus Plus node at

that address on the local Modbus Plus network.

For example, if the message contains Modbus address 8, it will be

sent to the Modbus Plus device at node 8.

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