RS-232 pump connections - DON'T USE THE DB9

Had a report recently from a customer who said my software constantly crashed. My software shouldn't' crash - ever but there will be problems from time to time - I can't test everything. When I learn of crash behaviour - I test and try to duplicate and then resolve the problem.

I asked the customer for a photo to check the cable hook up and some other diagnostic information. He very kindly and quickly got back to me with the items I requested.

pumpnetworkconnectorstocomputerhighlightThere in one of the photos was the rear panel of the pump, with the data cable to his communications port connected to the pumps' input/output port and NOT the RS232 port of the pump.

I admit I don't test my software for what it does when the cabling isn't correct.

This isn't the first time someone has used the DB9 for communications. I think the reason is simple - folks with a bit of experience of computers and equipment got used to the DB9 connector as being a communications port in the past.

Sadly, I don't have access to the customer's setup, so I can't test that cable and see if my software crashes because of this hook up - I can't imagine why it would - but I guess it depends a lot on the signals that were being passed into the communications port.

Update: Customer got the correct cable from his supplier and SyringePumpPro started working immediately!

How To Connect Pumps To A Computer


Parts list for connecting computers and laboratory pumps