Relay LED on, no continuity

[JinkerKing]

G'day, Am having trouble getting relays to switch. Bob is PMDX-126. Mach3. Gecko 203V. Oriental steppers. WinXP through LPT1. SheetCAM from TurboCAD Deluxe.
 Have been running this MechMate 8x4 for a few months mostly making plywood boxes with finger joints. Have processed more than 60 sheets of ply with a large China water cooled router spindle turning straight, 2 fluted 4mm bits. Quality of cuts has gradually improved whilst I tuned feeds, speeds, stopping on certain angles etc.
 Am setting up small plasma power source to experiment. My problem is that I can not get the plasma torch to fire. Have worked my way back to the relays on the PMDX-126. When the M3 command is received by Mach3 the PMDX relay led lights though no continuity or 'click'. Same behaviour on K1 and K2. Attempted a work around  and purchased an arduino compatible relay board. Ran it up on J6 pin 14 after removing jumpers from JP1 and JP2. Same behaviour. LED lights though no 'click' or continuity.
 The only slightly 'weird' thing about my machine is that the homing/limits are proxys, run hot, triggering relays, powered by an external 12v supply.
 Any help greatly appreciated.

[JinkerKing]

Further, have been running spindle 'manually' through VFD. Have auto zero 'Z' working.

[Steve Stallings]

If the LED beside the relay turns on and the relay does not click and does
not provide continuity through its contacts, something is wrong. The first
thing that comes to mind is the voltage that powers the relays being less
than it should be. This could be caused by trying to run a board set for
230 VAC from 208 VAC (two legs of a real 3 phase power system) or
caused by the power supply of the PMDX-126 being overloaded. Such
an overload could be caused by trying to run an Ethernet SmoothStepper
and a PMDX-107 at the same time, or by something about your proximity
switch setup.

You can check the voltage between PCgnd and +Vraw on J7. This voltage
should be 10 volts or greater.

[JinkerKing]

Steve, Thankyou for your quick response.
 I am driving the PMDX board from a parallel cable. No smooth stepper. I have purchased a PMDX-107 spindle controller from you though have not installed it at this stage. Am getting 245VAC at the mains terminals on the board and 11.7VDC across PC-gnd and +VRaw on J7.
 Re the proxys: My machine is a MechMate. The was a long discussion on the MechMate forum about how to hook up EStop, pause, resume and proxys. Near the end of the discussion they decided to run AC power to the EStops. I didn't like the sound of this so my implementation of the switches hookup uses circuits controlled by switches on the machine directly to inputs on the PMDX-126.
 The proxy set up is unusual though as roughly described by GeraldD. Each proxy drives it's own relay which, when activated, breaks the input circuit to the 126. This sub-system is powered by an external 12VDC supply. The unusual thing about this setup is that the proxy senses the guide rail and 'activates' when it passes over a hole in the rail. The idea is to protect the machine in a 'de-rail' state as well as serving as home/limits.
 I knew I needed to document the wiring, so have started to do this. I will also try disconnecting the proxy sub-system and check the 126's relay in this state.
 I have to go back to work as a long distance truck driver tomorrow so it may take a week to get all the above done.
 Any other suggestions in the meantime?
 Will get back to you when I have more info.

[Steve Stallings]

If the LEDs on the PMDX-126 beside the relays are working and the
+Vraw is good (yours is OK) then the relays are defective or your
measurement technique is not correct to confirm continuity. One
thing that comes to mind is the terminal strips. If you try to make
a connection to the head of the screw without the screw tightened
down, you may not get a good connection due to the way the clamp
in the terminal works.

[Bob at PMDX]

From your original post:

Attempted a work around  and purchased an arduino compatible relay board. Ran it up on J6 pin 14 after removing jumpers from JP1 and JP2. Same behaviour. LED lights though no 'click' or continuity.

Do you mean that when you connected the Arduino relay board to J6 on the PMDX-126, the relays on the Arduino board also did not close their contacts?

Bob

[JinkerKing]

Steve, Screwed down all terminals tested. None had wires in the terminals. No continuity on K1. (The relay K2 had a severe tapping to determine 'stuckness' and now emits an alarming sound when it is energised.) Do not intend using it any more.
 Bob, Yes. Same behaviour on the Arduino board. On PMDX/machine power up get a 'power' led on the external board. Then get 'active' led when Mach3 sends the M3.
 I'm using the pmdx_3Axis_pp_02 based Mach3 xml file. Tool selection 'plasma' from SheetCam. Could it be possible that my SheetCam/Mach3 configuration be sending problem M3 commands regarding the torch/spindle tool. Something like a 'spindle on' with no 'direction' interpreted by PMDX as a continuous high/low combination that may drive the relay led though not the relay coil? Just a thought.
 Have started the wiring diagram though have not got past the control/distribution box yet.
 Regards, Ashley.

[Steve Stallings]

If the K2 relay is emitting a whine or buzz sound, it is likely that
it is trying to follow a PWM signal or something else strange.

Please send us your current XML file so we can have a look.

Also a small Gcode file from SheetCam that exhibits the problem
would be helpful.

[JinkerKing]

Hi Steve, Back from Port Headland. Thanks again for your reply. Have attached the files a well as a couple of machine pics.
Regards, Ashley.

[Bob at PMDX]

I took just a quick look at the Mach3 XML file.  You have the spindle STEP and DIR signals mapped to Pin 14, as well as OUTPUT #1 and OUTPUT #2.  And OUTPUT #1 is controlled by M4 and OUTPUT #2 is controlled by M3.

So you have the spindle step signal (which is actually a PWM signal) fighting with the spindle DIR signal, fghting with M3 fighting with M4 for control of the pin 14 output.

If your goal is to have pin 14 go high (and thus energize the relay) whenever the spindle is running, do this:
(1) in the config->Ports&Pins, go to the "Spindle Setup" tab, and un-check the "Use Spindle Motor Output".  That will disable the spindle step/dir signals.

(2) It has been a long time since I've run Mach3, and I am not sure how it behaves if you have outputs for both M3 and M4 driving the same output pin.  So I would suggest at least for now that you disable "Output #1" in the "Output Signals" tab.  This will allow M3 to turn on the relay, and M4 will behave like M5 and turn off the relay.

This should allow the K2 relay on the PMDX-126 to work.  Once you have that working we can talk about supporting both M3 and M4, and possibly getting your PMDX-107 installed (which may help here).

Bob

[Bob at PMDX]

Oops - one more thing.  You have OUTPUT #1 and OUTPUT #2 configured as active low.  They should be configured as active high.  In the config dialog, click on the "Output Signals" tab and click on the green check marks in the "Active Low" column to change them to red "X"s.

Bob

[JinkerKing]

Bob, It's working! As you suggested, un-checked the "Use Spindle Motor Output", disabled "output #1" and configured "output #2" as active high. Have been able to switch both K1 and K2 successfully. Strangely I have not been able to switch the arduino relay board though that was not the goal. The I am now able to continue setting up the plasma cutter.
 Bob and Steve I can not thank you enough for your help, particularly as my issue turned out to be more Mach3 related than PMDX.
Regards, Ashley.