On Friday 15 August 2014 16:43:33 Andy Pugh did opine
And Gene did reply:
> > On 15 Aug 2014, at 18:19, Gene Heskett <[email protected]> wrote:
> > 
> > to the
> > contrary, cannot be loadrt'd using the names= option.
> 
> If I have this problem I generally put a "show funct" in the HAL file
> after the loadrt section to see what the functions have been named.
> 
I hadn't thought of that but did find the problem.  Among the various hal 
modules, there is apparently no good practice  document encouraging a 
uniform way to name pins, so we have a mish-mash of names in use.  I was 
so used to typing in0, in1 etc that it never occurred to my wee brain that 
the lut5 was using in-0, in-1 etc. Duh.

It, my aged wet ram, also has problems with wide input count devices, but 
a comment in the lut5 man page will I think, save me 2 module instances.

I have 2, 2 input and's made out of lut5's to confirm that motion.spindle-
direction and encoder.0.is-positive or is-negative agree.  But there is an 
error condition that can raise a hand if the code issues a huge slowdown 
in spindle speed that can cause the sign of the PID output to invert.  
That is a big slowdown, but can be done while tuning PID's.

This causes the Mesa SpinX1 controlled fwd/reverse relays to switch, 
throwing the full power of the controller into the motor trying to reverse 
it.  The controller, a $185 Gemini, survived only 3 such events before it 
punched the IRFP250N hexfet, a 200 volt 30 amp device.  So that is an 
error condition that I'll use to defeat the 2 input and's setup in lut5's, 
releasing the 3rd relay, which if energized, shorts out a 50 ohm 400 watt 
resistor in series with the motor.  And I'll do it based on the man page 
comment about leaving unused inputs open by feeding this true if dir is 
missmatched from an abs.piddir module into in-2 of both the forward and 
reverse path logic, which if the man page comment is true should cause a 
false output.

The idea being that ONLY if all conditions are correct, do I energize the 
relay the shorts this protection resistor.  So all failures are fail safe. 
(insert famous last words comment here)

Its all carved into the .hal file, and it runs but is not exhaustively 
tested yet.  And won't be till I get the BOB to 3rd relay wiring finished.

I am considering replacing the hexfet with a Vishay/Siliconix SiHW73N60E 
device, a 650 volt, 73 amp device with an even lower Rdrs(on), but haven't 
actually ordered about 5 of those yet.

Gate/Drain capacitance, and its effect on the gate driver also come into 
play, stressing the drivers ability to deliver that extra current, and 
prolonging the switching times causing the device to heat more.

I got the TLP127's yesterday (digikey ships fast) and made me a teeny pcb 
with a checkerboard pattern, assembling 3 of those opto's so I have the 
independent control of this 3rd relay, and something to hook the mist and 
flood signals to the outside world with.  But did not glue the board down 
anyplace yet, nor wire up the BOB outputs to drive them.  Too cold to work 
much longer in a t-shirt last evening.  Hard to do precision soldering 
when you are shivering.

So that's todays project but its colder than a witches teat for "out on 
the table on the shop's deck" projects yet, only 17C here at 10:30 AM.

Thanks Andy.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>
US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS

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