Build Thread: Ramsay CNC Plasma Question

[tblough]

When you say "put through the relay", how exactly are you connecting 1/2 to the output relay? Are you connecting 1/2 to the common and NO terminals?

[centroid467]

TorchArcOk should be an output from the plasma box to the control to tell it that the arc is lit and ready to cut. I'll have to check the PLC to see when exactly it applies but we typically recommend not using it on lower cost plasma units as that output may not have the best timing compared to observing the divided torch voltage.


I believe that you have it wired to the correct (normally open) terminals on the relay board and I'm concerned that it turned on when the machine was powered on before software was fully up. Please create a new report and post it so we can see your PLC and parameter settings.

[OceanFab]

report_3484E41A16E5-0112247823_2024-10-07_11-22-31.zip

(5.33 MiB) Downloaded 4 times

I've switched the 1/2 back to Out2 and it is consistently firing the torch when I turn the machine on, before CNC12 is started.
So the relay Out2 is tripping when the machine is started up, before CNC12.
I've disconnected 3/4 entirely and it still fires before the software is running.

[OceanFab]

When you say "put through the relay", how exactly are you connecting 1/2 to the output relay? Are you connecting 1/2 to the common and NO terminals?

https://photos.google.com/share/AF1QipM ... VqZ3VPZXB3

[centroid467]

TorchArcOk input does not do anything to inhibit TorchOn except when running and the input goes out - this would register with a torch fault message. Since you don't have those messages in your log, I am going to guess that is not the problem.

I have taken apart some lower cost plasma units to figure out what the heck is going on in the CNC interface connections (arc voltage divider, arc start input, arc ok output) before. Typically they provide voltage for the arc start signal so all you need is a relay to close the circuit to start the arc. Arc ok output is typically a relay so it just has to go to the Acorn input and power supply common. Both signals should not care which wire goes to which side of the relay or to the input or common.

This one is probably not different but lets try to find out more. With pins 3/4 of the CNC connector wired to Acorn's TorchArcOk input and input power supply common, what is the voltage across the TorchOn connections from pins 1/2? Is it still around 2V? Is it any different without the TorchArcOk hooked up?

[OceanFab]

Having a rough time. Across the com and NO on Out2 I get 0v when the VCP is TorchOn.
To understand, I loosened the screws on the top of the Phoenix.
When I do, there is a point at which the relay switches and the torch goes on.
When I try to tighten it, the torch goes off. Loosen it, torch goes on. Tighten it, off...
I have switched the phoenix connector only, same Out2, with another phoenix and same thing.
Is it interference of some kind? Now I have turned the TorchOn to off, and taking the phoenix in and out turns the torch on again???
Ghosts?
Taking phoenix in and out, with TorchOn off and even CNC12 off, torch is firing. If I disconnect torch, it fires when the two 1/2 are brought together, no problem.
Should I go through the DB25 on the Acorn, perhaps the relay board is out.

[centroid467]

Having a rough time. Across the com and NO on Out2 I get 0v when the VCP is TorchOn.
To understand, I loosened the screws on the top of the Phoenix.
When I do, there is a point at which the relay switches and the torch goes on.
When I try to tighten it, the torch goes off. Loosen it, torch goes on. Tighten it, off...
I have switched the phoenix connector only, same Out2, with another phoenix and same thing.

That almost sounds like it is expecting a normally closed contact or there is a break in the wires that shows up when force is applied or some other connection issue like the rising cage clamp in the Phoenix connector is only grabbing insulation. However, none of these make any sense when trying to explain it working when loosened AND when the Acorn is powered up but not connected to the software. This really is a puzzle.

[OceanFab]

Any way to test/diagnose the relay board?
How does Out 2 on the DB25 board connector work? Should I just connect one of 1/2 to com, and another to this Out 2?
Can I send Out 2 from the DB25 to an alternate relay?
I haven't tried anything yet, afraid to fry the DB25.
Just ordered this for tomorrow, www.amazon.com/SunFounder-Channel-Optoc ... 00E0NTPP4/
as an alternate relay.

[Joey]

You can Alter the State of an Output in the Alt-I I/O diagnostic menu in CNC12.

Check for continuity between the center COM terminal of the output and either the NC or NO terminals on either side of the COM.

By changing the output state in the Alt-I Diagnostics menu you will see Continuity gained or lost when the output changes state.

[OceanFab]

Hi, Joey,
For Out 2, whether I force the led green or red in the PLC diagnostic menu I am getting a closed switch, which may account for the plasma cutter turning on when the machine starts without the CNC12 running.
When I switch the black wire from the first terminal to the 3rd (NC usually), and I test the continuity, I get a closed switch, but the act of testing the terminals turns the torch on. Maybe the tester is making a connection?