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Modbus Plus Unsolicited Support

Can your OPC server accept unsolicited Modbus Plus data?

The TOP Server Modbus Plus driver can function as a slave and receive unsolicited data from the PLC. A single slave path can be configured per SA85 card using the format DS.1.0.0.0.0. Defining a slave path enables the host PC running the Modbus Plus driver to simulate a PLC device on the network capable of responding to read/write requests from other devices. Other devices can communicate with this simulated device by opening a master path to it.

When a slave path is enabled, the Modbus Plus driver will enable eight slave paths on each SA85 card. This allows your remote PLCs and other Modbus Plus devices to access the slave memory of this driver using any of the eight slave paths.

In terms of an MSTR instruction, you can specify a path of 1 through 8 when defining what path to connect with on the SA85 card serviced by this driver. This can be useful if your application has a large number of remote devices that will be sending data to this PC. If this is the case, you can use the 8 slave paths to distribute the load from remote nodes.