Syncronous Heart Beat SOAP Service in PI

Looking for any comments or idea's

Ive been asked to provide a Heart Beat SOAP service in PI. This heart beat service needs to be a sync service with certain custom fields that include a unique identifier and a timestamp.

My initial thoughts was to setup the SOAP Sender channel SYNC pass the message into BPM the pass back a response. My main issue with this its a little too heavy/complex for a simple heart beat service (no data).

Second thought was to create a BAPI on the PI ABAP stack and expose it as a webservice, my main issue with this is it wont actually represent the state of the adapter engine (Webservice on ABAP might be up but the Adapter engine will be down).

I cant be certain what the service is being used for as the service is being called by an external party who have asked for this service, all I know is that a SYNC service is needed that will map in system time with a unique identifier.

Thanks for your comments.