SPC (Statistical Process Control) data connector info wanted
Message #1 Posted by Ellis Easley on 16 Apr 2003, 6:41 a.m.
Does anybody know the pin assignments for the little 4 position connector on some digital calipers and indicators? I have done some Google searching and I have learned it is called the SPC interface and might have originated with the Mitutoyo company. There is a big industry supporting the connector with cables, computer interfaces and software but none of the websites I found gave the pinout. The connector on the caliper is a PCB edge with 4 gold plated contact fingers and the mating connector, which I've only seen in pictures on the web, has 4 spring contacts reminiscent of one side of the connector on an HP41 module.
I did find this page which describes a homebrew convertor to make a measuring device with another type of interface look like an SPC interface device. It includes a .pdf with a schematic of the convertor and good descriptions of the two protocols, also C source code and 8051 object code for the micro on the convertor. However, the connector it describes is the "other end" of the cable that plugs into a Mitutoyo controller:
http://www.matronics.com/cncscale/
I think I will be able to figure out the pins by experimentation but if anybody can tell me what the assignments are I'd appreciate it!
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