The eviateg OPC field devices provide (depending on the model) the following data points:
- digital switching inputs
- analog voltage and current inputs
- voltage sensors (24 V main supply and rechargeable battery)
- temperature sensors
- counter values
Status changes on these datapoints are tagged with a time stamp and are transmitted to the OPC server eDOS either immediately or as part of a cyclic routine message via
The OPC servers provides the status of all datapoints of all registered field devices with their respective time stamps in a tree structure to an OPC client.
The OPC client is integrated into a software which processes the data point informationen, eg.
- representing them graphically (visualisation)
- taking actions within a control center
- archiving measurement values
The OPC server eDOS supervides furthermore if all field devices connect regularly with a cyclic routine message (eg once per day).
As necessary, the control center software can change via the OPC client the values of writable data points on the OPC server, which are assigned eg. to output relais of an OPC field device. The OPC server establishes then connections over the approrpiate network to the OPC field devices and forwards commands to switch the respective outputs.
With an "OPC Relais" function it is possible to map the state of the inputs of an OPC field devices to the outputs of an assigned second field device.