Configuration of communications

Architecture

Communication in D2000 is handled by the D2000 KOM process. The latter has as children communication lines (serial, TCP, UDP, OPC, file, etc.), these have children communication stations (on which the communication protocol is defined) and communication stations have children measured points (we call them I/O tags).

Note: this hierarchy is based on the serial communication model, where the communication line corresponds to the medium (or the serial port through which the line is accessed) and the stations correspond to the devices (PLC, RTU) connected to the medium.

Simple applications have a single KOM process which is the parent (grand-parent, grand-grand parent) of all communication objects. This process has an autostat enabled and is started by the D2000 Server when the D2000 system starts.

More complex applications may have dozens of communication processes (local and remote) licensed and running. Some communications require that the D2000 KOM process be run under a specific Windows user. An example is the OPC DA protocol (OPC Classic) or various file communications for accessing a remote server.

Communication objects are configured in the D2000 Cnf tool.

First, it is necessary to create a new KOM process or use an existing one (e.g. SELF.KOM).

Subsequently, it is necessary to create a communication line whose parent is the selected KOM process. It is important to select the correct line category (if it is necessary to change it later, this may require a restart of the KOM process). The support of communication lines for individual communication protocols is in the document Communication Protocols.

In the next step, create a communication station whose parent is the configured line. The communication protocol and (for most communication lines) the station address are set at the station.

For some communication protocols, it is possible to set the protocol parameters in the line or station configuration.

The details of the configuration of lines and stations are in the documentation of individual communication protocols.

Finally, the I/O tags are configured - the parent of the  I/O tag is the communication station. The type must be defined for the I/O tag (input/output type digital/analog/integer/absolute time/relative time value). Filters, conversion to technical units, process alarms, and other parameters can be configured at the I/O tag.

On the I/O tag, it is also possible to configure the status text (converting a number to a text constant for the display) and the transformation palette (which determines the standard format during display, unless it is changed by a format mask).