H.E.S. 24NCS Lathe (24 X 60) conversion

canner wrote: Blue 0v goes to ground
Brown power supply goes to +5VP
Black OUTA goes to ENCA+
White OUTB goes to ENCB+
Orange OUT goes to IDX+ (Pin 13)
Shield Ground will connect into the main grounding bar

I found this in an old email:
"If the inputs are jumpered for TTL levels you must leave the -inputs
unconnected. The + inputs have 2K pullups to 5V so will be in a high state if
left open. "

So you seem to be correct.

I would source the encoder power from one of the protected (+5VP) pins on the TB3 terminal block, and the GND too.

Okay, not making any progress and think this is at the very least a major part of the problem. The encoder says it runs on 10-30 vdc, the power coming off of the 7i76 is 5 volts. Will it cause a problem if I route 24vdc power to the encoder but then run the A, B, and Z signals to the 7i76?


Thanks

The paperwork on the encoder says that the output is power supply voltage -4v on the high and 2 v on low. Will this be to much for the 7i76? I could probably also pull 10v off of the vfd, not sure if that would work but might be a solution without having to wire in another transformer. Any help is appreciated.

canner wrote: The paperwork on the encoder says that the output is power supply voltage -4v on the high and 2 v on low. Will this be to much for the 7i76? I could probably also pull 10v off of the vfd, not sure if that would work but might be a solution without having to wire in another transformer. Any help is appreciated.

I don't know the answer to that question. I suspect that the only one who really knows is PCW.

Looking at the encoder data sheet it says that the encoder outputs are push-pull totem pole.
So, whether you can run the encoder at 10V or not depends on whether the encoder input pins are safe at more than 5V.
What are you using for Field IO voltage? 24V would be rather more common than 5V for limit switches and such.

2V low will not work with the 7I76 inputs (they have a TTL input threshold = 1.6V)
What I would do is run the encoder from 24V then make a set of resistive dividers for A,B,Index
These dividers should be close to the 7I76 for noise immunity (that is most wiring should be done at the 24V level)

24V ENC SIGNAL --> 2K 1W resistor --> 7I76 encoder pin --> 390 Ohm 1/4W resistor --> ground

This is a approximate divide by 6 ratio so instead of 20V high and 2V low
you should get about .5V low and about 4V high
(offset somewhat higher than the divider output because of the 7I76s pullup resistors to 5V)

Thank you PCW very much.

So I went to Radio Shack this morning, seemed the only chance in this small town and looked at what they had for resistors. The closest I could come was 2.2k 1/2 watt for the signal ends and 333ohm 1/4 watt for the ground. I hope this is close enough. in the 1 watt size for the signals they only went up to 1k. If this will not work I will order the resistors online.

I only had time to solder in the resistors and check it out a little bit. With the resistors in and the spindle turning, I was getting about 4.5v on the signal wires. This is progress.

I went to the front of the machine and tried running a g33 and got nothing. I only had a few minutes to try looking for the signals with the hal meter and no luck. Not sure which I should be looking at but tried to find the pin 16 that Andy mentioned but could not, skipped from 15 I think to 17.

So possibly something in the hal file or wiring. I should have more time to look at this tomorrow. Any suggestions would be greatly appreciated. Thanks