How to discover unknown HDLC addresses?

If you ignore the HDLC addressing scheme of a meter, then a possible solution is to use the custom application that should be provided by your meter's manufacturer to connect to their meters and then to ''sniff'' the exchanged HDLC frames using any appropriate program as for example ''PortMon''. The first frame sent to the meter is a SNRM HDLC frame and it already contains all the required addressing information.

If you have this frame, then copy or paste it without spaces or any other characters in the following text box and click the button. This will give you the addressing information.

For example, with this (SNRM) frame...


...we get this result:

Addresses of the SNRM frame

As the SNRM frame goes from the client application to the meter (server), the SRC address is the client's address and the DST is the meter's address. Here, the addressing scheme uses 4 bytes, the upper address (=logical device address) is 1 (=management logical device) and the lower address (=meter's physical address) is 17.

If the addressing scheme uses only one byte, then only the upper part is matters. Then the output is (for example): SRC=16 DST=1.