Mix and match

The little chappy in the photo is no ordinary cable its a USB converter that costs about 1000 Norwegian Kroner, a vital link between my old PASCO science workshop interfaces and a modern day computer. One day I'm going to have to do a serious upgrade but for now I am making do with the old stuff. The problem is not so much the interfaces but the sensors. To use my old sensors with a new interface would cost about 2000 Kroner for the adaptor plus USB link. What I really want is the new 850 universal, not sure of the price but I guess it's not cheap. Will also be trying out Capstone software which is PASCO's new flagship software, it's available here for 60 day free trial.

I'd be happy to continue using the converters for ever but they are starting to play up a bit. The other day it started to become a bit ridiculous. Students were having a lot of problems connecting to the interfaces. I usualy manage to make them work by simply plugging in and out a couple of times, much to the amazement of the students who think I must possess some magic touch. After a while it became apparent that it was the combination of cable and interface that was the problem. A cable that didn't work for student A was fine for student B. By randomly mixing and matching I usually managed to get something off the ground. I was talking to one of my students, Patrick, about this and he reckons that the connectors send the same data along two pairs of pins. With wear and tear the sockets and pins get broken however they still function as long as two of the pins connect with two sockets. The problem is if the working sockets don't match with the unbent pins then you don't get a connection. Well it sounds possible and the solution is:
Find out which pairs of cable and interface work and always pair them together.

Well it's worth a go but I'm not looking forward to the job of matching cable with interface, what happens if I am left with a pair that doesn't match?