Case 1: Devices with small APDU size

MS/TP or BACnet over LonTalk devices support only small APDU (Application Protocol Data Unit) sizes. MS/TP supports a maximum of 480 bytes, BACnet over LonTalk only up to 206 Bytes.

The maximum number of parallel requests is set to 1. This means only 1 request is sent and the response is awaited before continuing with the next request.

If the APDU size is less or equal to 480 bytes (e. g. MS/TP devices), then the ReadPropertyMultiple threshold will be set to 5. Change-of-Value will not be used in this case.

The number of properties per RPM request is limited 20 properties.

If the APDU size is less or equal to 206 bytes (BACnet over LonTalk devices), the number of properties per RPM request is limited 10 properties.