spike relay problem?
 

On the new control system cRIO we're having a bit of trouble getting the spike relays to work.

We have the code setup to run the relay forward when one button is pushed, and backwards when another is pushed. The forward button works and the relay changes, however, the reverse doesn't. The code is working, you can see the reverse light on the digital sidecar turn on, but the spike will not change like it does for for forward.we've vhecked and replaced the pwm cable several times.

My beleif is that the problem lies in the libraries controlling the pins for the relay switches incorrectly. Has anyone else experienced this problem?

Re: spike relay problem?
 

If the light on the digital sidecar is changing as expected, I don't think there's a software issue.

What do you expect to see from the Spike, and why do you expect that? What is it doing instead?

Re: spike relay problem?
 

That was my conclusion too

I expect the relay to go forward, reverse and stop.
it only goes forward and stop, even though the digital sidecar is sending the signal, the spike isn't doing anything.
and, yes. I have tried using a different spike relay and cable.

Re: spike relay problem?
 

This may seem like a dumb question but are you using a newer Spike? There was a model change several years ago and previous models responded differently than the modern ones. The old ones were labeled with a red label as I remember.

Re: spike relay problem?
 

Are you trying to simultaneously drive the Spike both forward AND reverse?

If you're trying to drive a motor and you set both FWD and REV, the motor will have both leads driven to battery voltage which means 0V across the motor.

You might need to check the logic in your software since you only be asserting either FWD or REV with this type of application.

Russ

Re: spike relay problem?
 

Please tell us what colors the light on the Spike is showing. Yellow means stop. Green means forward. Red means reverse. Off means both forward and reverse at the same time, which is probably what you're telling it to do when you think you're telling it to go from forward to reverse. It's just like stop, except that both outputs are at battery voltage instead of both being at no voltage.

A Spike has two completely independent relays. Forward and Reverse are not two different states of the same relay. They are separate relays which each can either be on or off. If you want to "go in reverse", you have to turn the reverse relay on while simultaneously turning the forward relay off.

Re: spike relay problem?
 

I don't know the electrical pin out of the SPIKE control signals, but you could take a volt meter out and check to see if it is sending the signal you expect. I would expect that the manual has that information, or someone on CD knows.

Re: spike relay problem?
 

*sneeze*

Re: spike relay problem?
 

you should try and bypass the spike and use a victor control. we just did that today and it solved our problem. Now we can go forward and reverse.:D

Re: spike relay problem?
 

Did anyone ever figure this out? I am having the same problem. In the programming I have it set that one button is forward, another reverse and when nothing is pressed it is off. The digital side car responds as expected, green light forward, red light reverse, and no lights when off. The spike (blue label IFI) responds to forward (green light on spike, +12 volts), but does nothing when reverse is sent to it. no clicking no nothing. Sending the kOn command turns on both the green and red light on the digital side car and the green light on the spike.

Why no reverse? such an odd problem.

when the command kOn is sent is it activating both internal relays? so I should be getting 12 volts from both output pins when compared to ground on the power distro panel? Just trying to figure out a way to trouble shoot and see if one of the relays are bad, I do not have another spike on hand at the moment to test by just swapping them out.

Re: spike relay problem?
 

Your code passes muster if the Digital sidecar Relay LEDs are performing as described.

The Spike should reflect what the Sidecar LEDs are doing, although I think the Spike should be yellow for neutral when the Sidecar LEDs are both off.

It sounds as if the code is working through to the Sidecar.
Any of the parts after that could be causing a problem:

• Sidecar itself (test the Relay pin outputs with a multimeter- relays are a constant 5v on both the red & green signal pins when they are active, 0v when not)
• PWM cable (test at the far end with a multimeter)
• Spike (test 12v output on M+ & M- lines to ground)

P.S. It sounds like the red signal line isn't getting through for some reason.

Re: spike relay problem?
 

all sound like excellent troubleshooting techniques, will perform and report back.

Re: spike relay problem?
 

Either one of the wires in the PWM cable may have a poor connection or the SPIKE is damaged.

Make sure that the PWM cable is seated all the way into the spike with the black wire (- on the Digital Sidecar) next to the "B" on the SPIKE.

Pull the PWM cable out completely. Check each wire end-to-end with an Ohmmeter to make sure there is not a broken wire.

There may be a dirty connection. Unplug and replug the PWM cable 5-10 times at each end. Try rubbing a red pencil eraser on the pins of the PWM cable to clean them.

Set your voltmeter to DC Volts. Hold the black probe on the pin with the black wire of the PWM cable. Hold the red probe on the middle pin and have your software enable forward then reverse. You should see about +4 V in one direction. Move the red probe to the third pin and have your software enable forward then reverse. You should see about +4 V in the other direction. If this is OK, your signals are getting to your SPIKE but it is not responding due to a bad connection between the SPIKE and the PWM cable or damage to the SPIKE.

In the "Braking Mode", both relays in the SPIKE should be energized. Set your voltmeter to DC Volts. Put the black probe on the "-" terminal of the spike (input from the PD Board). Put the red probe on the "M+" and "M-" terminals. You should see +12 V relative to the "-" on both output terminals.

It is possible that the circuitry for one direction is damaged in your SPIKE. The circuitry for forward and reverse are largely independent so it is possible to have a SPIKE where only one direction works. Replace it with another SPIKE.

I just noticed Mark has posted similar advice.

Re: spike relay problem?
 

I believe that Al is on to something here. We had a similar problem - swapped everything (spike, code, cRIO, wire, etc.) and then tried a VEXPro Spike (we had been using older IFI redlabel/bluelabel Spikes). Suddenly, everything worked as expected.

- Mr. Van
Coach, Robodox

Re: spike relay problem?
 

To back up Mark, almost always when the DSC is showing the expected LEDs the problem lies with the PWM cable.

Re: spike relay problem?
 

Or, in this case it looks like a spike issue. the pwm cable checked out fine, but just in case I tried another. I got +5 volts from red/white wires with corresponding button presses that activated forward and then reverse. Seams like something in the spike has failed. To be fair its a fairly old spike pulled off a robot from years back.