Re: Signal light trouble-shooting
 

Sorry, Al, we actually have tested out the Signal Light. On the first few attempts, using the original schematic from the Tips/Guidlines, we ran into problems with getting the lamp to light.

After scratching my head for a bit, I found the problem had to do with the labelling on the relay. I think I had accidentally looked at the small '14' to be Port 4 and had wired it incorrectly.

As Al said, if you guarantee that you have the 5V and GND sides correct, and they test out fine with a DVM, then it -should- be working fine. The relay LED definitely lit up when operating with/without the signal lamp attached.

I know that didn't help much, but it may be worth confirming that the wires are in the right ports on the relay. The labeling on the relay itself is a bit hard to read.

-Nate

Re: Signal light trouble-shooting
 

Al,
We tried a new pwm - no go. We also tried it on the old robot (forgot to mention that), still no go... we hooked it all back up with new pwm and ran the voltage test and got nowhere near the 5v expected. At this point I'm going to borrow a relay from a nearby team to see if that's the issue. I'll post this evening and let you know.
THANKS.

-Rich

Re: Signal light trouble-shooting
 

Well, we got it to work using a PWM straight to the light with the correct things jumped on the light itself. We basically did everything the schematics in "Guidelines..." said to with the exception of using the relay.

Re: Signal light trouble-shooting
 

Here's another little interesting twist that may matter ... Al, I'll need you on this one.

The kit of parts checklist lists 700-SKOC2Z25 as the relay part number.
The relay I'm holding has a part number of 700-SKOZ2Z25.

In checking the Rockwell website, both parts are listed (and seem to have the same specs) here:
http://www.ra.rockwell.com/en/epub/c...677/print.html

Should/does this matter?

Re: Signal light trouble-shooting
 

Rich,
The relay you have in your hand is a device intended for switching AC loads of 100-240 Volts. In addition it has zero cross detection so it is unlikely you can turn it on until you have both the control voltage and a sine wave AC load voltage that passes through zero volts. (this is a technique used to eliminate noise output when the relay closes at the high voltage point on the sine wave.) I am guessing that is why you can't turn it on with the device wired properly. The correct relay should help the problem.
Al

Re: Signal light trouble-shooting
 

Thanks Al & Nate...
I sent the info to the official Q&A so they were aware and to see if they'd replace it. I'll keep everyone posted, but until then look to see if the part number is correct ... that "Z" instead of the "C" certainly makes a difference

Re: Signal light trouble-shooting
 

Sorry we couldn't get you an answer until late on a Friday. Maybe next time. Good Luck!

Re: Signal light trouble-shooting
 

Something else that you may have already considered, but do you know for a fact that each of the wires in the cable you used is good end to end? So far I have found two bad 3-pin cables out of those supplied in the kit this year.

With your cabling connected, and the power turned off, you could use a DVM to confirm that the wiring out of the RC is actually making it to your light & solid state relay. The wiring to the 5 pin headers on the RC are all identical, so with the wiring connected, you can probe the pin on the immediately adjacent header and it will mirror that of the one you are connected to.

If you are satisfied that the wiring is correct, you can use a DVM (or better yet an oscilloscope) to see if you can see the pulses, representing the light blinking, are actually coming out of the RC. If I remember correctly, the pulses are on the order of 100ms in length, so your DVM should show some non-zero voltage as a result of that, and if it responds quickly enough, may even be able to show you the pulsing. If you had an older, analog meter movement, multi-meter, the pulsing would be even easier to see.

Re: Signal light trouble-shooting
 

We just discovered that we have the A.C. relay instead of the D.C. relay. Any thoughts on how to obtain the correct relay? We are going to try to get one from Allen-Bradley, however time is very short!

Thanks,

Mike

Re: Signal light trouble-shooting
 

Mike,

I would start by contacting FIRST.

Mike

Re: Signal light trouble-shooting
 

Mike - Team Update #9 tells you how to let them know you have one:

Re: Signal light trouble-shooting
 

We also received the relay with the wrong part number, and have already contacted FIRST. Since teams will likely not be mounting the lights to the robot 'till the last minute, I STRONGLY suggest everyone to take a look at the relay and check which one they got when we still have the time.
I'll be contacting the other Brazilian teams to do so ASAP, I assure you.

Regards,

Re: Signal light trouble-shooting
 

Thanks for the information Aidan. My students just gave me this update!

Good luck in the competitions.

Mike

Re: Signal light trouble-shooting
 

Aiden already posted the update 9 info. To follow up, after I sent an email about the wrong relay, FIRST responded within hours and is mailing the team the correct part.

Re: Signal light trouble-shooting
 

We received the correct part from FIRST today. The light fired right up - problem solved. Please check this part number if you haven't already wired your signal light.