Quote:
Originally Posted by zano_villa
If I have implemented a MANUFACTURER SPECIFIC PID in my device, I need to list it otherwise the controller has no other way of knowing about its existence. Am I right?
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Yes, if you want controllers to be able to use a Manufacturer-Specific PID, then you should include it in the list of supported parameters.
However, sometimes there are non-public PIDs that manufacturers don't want to be visible. For example, there might be a calibration PID that is only intended for factory use.
Also, there might be a PID that is only intended for use when someone is on the phone with your support team. Support might tell the user to send a specific PID and then read the response to help troubleshoot a problem.
For this reason, many controllers allow you to send a specific HEX PID, even if that PID is not in the list of supported parameters.
Quote:
Originally Posted by zano_villa
And what about the STATUS_ID_DESCRIPTION of a MANUFACTURER SPECIFIC message? How does the controller know in advance the implemented STATUS ID to be able to request its description?
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A controller should not need to know every supported Status ID in advance, it can request the STATUS_ID_DESCRIPTION when it first receives that ID.
For example, if a responder reports status ID 0x9345, and the responder doesn't know what 0x9345 means, then it can request the status ID description at that time