Supported Services
This window displays the supported services of the peer device.
ReadProperty
Cyclic polling is performed to determine the property values. Read Property reads only individual properties. Read Property Polling is therefore very slow due to its principle.
RPM = Read Property Multiple
RPM is a cyclic polling that polls multiple values at once to determine the property values. This process is faster than polling with Read Property. In some cases, the PropsRPM value must be lowered to a lower value, especially for devices with limited resources.
COV = Change of Value
This setting uses COV to poll the property values (Present Value and Status Flags).
Note: Some devices, especially MS/TP devices, may support COV only for some, not all, objects contained in the device. In this case, deselect COV from the supported services and, if necessary, add COV support in the PLC code only to the objects that support COV. In the data sheet of the BACnet device you will find the corresponding objects. If you are not sure, disable COV and use RP/RPM polling instead.
COV-P = Change of Value Property
With this service TwinCAT subscribes as a client to individual properties. Note: Not all BACnet devices support this service!