A customer is looking at our DS9808 scanners, and on some of their older POS they require the scanner to connect via the PS2 port. We have already tested this with them and found it works fine without having to use a power supply.   This has surprised them as all other competitive scanners they have tried require a separate power supply.

What they are now asking is for some formal assurance from us that explains why we do not require a power supply.  I have searched our systems etc for something that will allow me to answer them with confidence, but cannot find anything. In the manual it refers to the power supply as ‘optional’ with no further qualifications. Is there something available that confirms we do not need a power supply - this is possibly a real competitive advantage we have.