Power Delivery Tester does not accept new source capabilities after initial Attach

[AndrewRogers]

Hello,

The USB Power Delivery specification requires that USB-C sink devices adjust to new source capabilities any time that they are issued by the source.

The PassMark PM125 USB Power Delivery tester does not do this. If a source changes the source capabilities any time after initial connection, the sink must make a new selection. Take a battery powered PD power bank for example. When fully charged, it may offer 20V, but after it has become discharged, it may strip the 20V option because it is inefficient and no longer has sufficient charge.

The PassMark PM125 USB power Delivery tester should be addressing this by going to 5V when new source caps are advertised, for example, then reflecting the new source capabilities.

As the device operates today, I cannot reasonably use the PM125 for testing of my products.

Are you aware of this issue? If yes, when will a fix be implemented?

Thanks,
Andrew Rogers
Microchip Technology

[HamidK (PassMark)]

When a new capability message arrives and a previously selected profile is no longer available, the tester should select the closest voltage. For example, if available profiles are 5v, 12v and 20v, if 20v is not available, then 12v should be selected.
Can you please let us know,
- what firmware version you have on the tester?
- list of capabilities after connection
- list of capabilities once the battery is discharged