Modbus Source System

Definition

You can use the Modbus source system to set up a connection between PCo and programmable logic controllers (PLC) or other devices. This allows you to connect one or multiple devices to PCo as a data source to query or monitor specific tags. A Modbus source system can be used for query and notification processes.

The communication of the Modbus source system is based on the Modbus protocol that is used as standard for the communication with programmable logic controllers. Data communication with the source system is in the form of message frames.

Use

You can use the Modbus source system to forward data directly from the device to PCo. This data is sent to PCo in the form of data streams. The data stream is divided up into individual message frames. A message frame corresponds to one message. In the case of serial communication, the individual message frames are separated from each other with defined silent intervals. (See also: General Form of Message Frames.)

Data Transfer

The Modbus agent supports the following types of data transfer:

  • TCP

  • Serial communication

Functions of the Modbus Agent

The Modbus agent supports the following tag features in the PCo system:

  • Retrieve

  • Store

  • Mass Store

  • Subscribe

  • Unsubscribe

  • Native Mask

  • Groups

  • Secondaries

  • Metadata

  • Aliases

Tabs

The following tabs are available for configuring a Modbus source system: