Liberty is an inherently offensive lifestyle. Living in a free society guarantees that each one of us will see our most cherished principles and beliefs questioned and in some cases mocked. That psychic discomfort is the price we pay for basic civic peace. It's worth it. It's a pragmatic principle. Defend everyone else's rights, because if you don't there is no one to defend yours. -- MaxedOutMama

I don't just want gun rights... I want individual liberty, a culture of self-reliance....I want the whole bloody thing. -- Kim du Toit

The most glaring example of the cognitive dissonance on the left is the concept that human beings are inherently good, yet at the same time cannot be trusted with any kind of weapon, unless the magic fairy dust of government authority gets sprinkled upon them.-- Moshe Ben-David

The cult of the left believes that it is engaged in a great apocalyptic battle with corporations and industrialists for the ownership of the unthinking masses. Its acolytes see themselves as the individuals who have been "liberated" to think for themselves. They make choices. You however are just a member of the unthinking masses. You are not really a person, but only respond to the agendas of your corporate overlords. If you eat too much, it's because corporations make you eat. If you kill, it's because corporations encourage you to buy guns. You are not an individual. You are a social problem. -- Sultan Knish

All politics in this country now is just dress rehearsal for civil war. -- Billy Beck

Monday, June 30, 2003

Beware of Engineers with Screwdrivers

Sometimes I really hate my job.

I'm an engineer by profession. I've got the State license and everything. I've got a customer's machine that refuses to behave. It's got a (Star Trek Technobabble Alert!) single-ended 1024ppr quadrature encoder on it that yeilds 129 pulses per inch - most of the time. Except occasionally when moving in one direction, it will drop some counts. Like several inches worth. And since we're trying to measure to 1/64" accuracy, that's not a good thing.

The encoder is connected to an Allen-Bradley high-speed counter card that just counts, 0-999, then rolls over. The counter card communicates with an Allen-Bradley PLC 5/20 processor that totalizes the count. There are three other IDENTICAL encoders on the machine, and they all work hunky-dory. We've changed the encoder, we've changed the high-speed counter card, today we changed the CABLE.

It's still thumbing its nose at us.

(Edited to add: It's not mechanical, either. Rack & pinion gearing, positive keyed zero slip coupling. Anybody got a chicken to sacrifice?)

UPDATE! Problem solved! Of course, after the fact it was something simple, and blindingly obvious - the 5VDC power supply was only putting out 3.5V - just barely enough to make the encoder card work - most of the time.

Engineers with screwdrivers? Should be engineers with voltmeters.

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