RoboRIO unable to detect Jaguars wired through CAN

[Tyler Scheuble]

We are switching to Java this year and we have been trying to set up jaguars on our testbed. In the web dashboard we are able to recognize the PCM and the PDP, but we are not able to recognize our jaguars.

We have updated the version of our jaguars from 107 to 109 but it didn't help.

Picture of our testbed setup and web dashboard are both attached. I don't know if this could be a firmware issue on the roboRIO side or a wiring issue but we have been able to connect to the jaguars through BDC-COMM so we could update the firmware.

EDIT: Attachments didn't work so here is screenshots:
http://puu.sh/eEZ2P/b558060a05.png
http://puu.sh/eF3tb/18f327c530.jpg

[Joe Ross]

I don't see any attachements

[Tyler Scheuble]

Attachment uploading failed so I posted screenshots. My bad.

[Jefferson]

It's likely the hi/lo wires are swapped through the jags. Swap the hi/lo wires at not the PCM and roboRio.

[Tyler Scheuble]

We checked the wiring and the hi/lo wires are correctly wired according to the manual.

[ozrien]

Looking at the pic, the wires look backwards to me.
-Center Jaguar 4, on the harness between RIO and Jag
-On the left RJ11 (the one that doubles with RS232) CANL is on the inside (closest to the LED). But if you follow the inside of RJ11 cable it looks like it mates to yellow, not green.

I could be wrong though, there's only so much resolution.

[Jefferson]

We checked the wiring and the hi/lo wires are correctly wired according to the manual.

How did you confirm this? A quick and definitive test is to swap the wires at the roborio and PCM. I know the colors won't match, but it switches the hi/lo through the Jag part of the network. If that works out, then you can fix the cables between the new components and the Jags.

[Tyler Scheuble]

How did you confirm this? A quick and definitive test is to swap the wires at the roborio and PCM. I know the colors won't match, but it switches the hi/lo through the Jag part of the network. If that works out, then you can fix the cables between the new components and the Jags.
We originally checked the colors and found them to be correct but we just swapped the wires and it caused us to lose communications to the PCM and the PDP which we had before.

The thing about the situation that confuses me the most is we still have comms to the PCM and the PDP while the wires are hooked into the jags but it is almost like the roborio is ignoring them entirely.

Here is a current screenshot of our web UI:
http://puu.sh/eQY8J/bd1a33ddcf.png

[ozrien]

We originally checked the colors and found them to be correct but we just swapped the wires and it caused us to lose communications to the PCM and the PDP which we had before.

The thing about the situation that confuses me the most is we still have comms to the PCM and the PDP while the wires are hooked into the jags but it is almost like the roborio is ignoring them entirely.

Here is a current screenshot of our web UI:
http://puu.sh/eQY8J/bd1a33ddcf.png

That's not confusing. What I think I see in your photo is...
RIO(L) - Jag(H) - Jag (H) - PCM(L) - PDP(L)
RIO(H) - Jag(L) - Jag (L) - PCM(L) - PDP(H)

So of course PCM/PDP work one way. Then again without being there its hard to tell. When you flipped did you see the Jags in the roboRIO web-page config?

Anyway it really shouldn't be this difficult. At this point I would just connect the RIO to one Jag only and get that working. Are these out-of-the-box Jags? Where they ever used before? If so were they working on can or pwm?

[ozrien]

When you connected with BDC-COMM was it over serial or CAN? I mean if you BDC-COMM (rs232) to one Jag, can you discover the second Jag over CAN?

When using BDC-COMM the Jag you rs-232 connect to is the gateway, but you should be able to discover/setid the other Jag on the CAN bus. You should be able to discover each Jag using the other as the gateway in this fashion. Using only rj11 cabling, there shouldn't be a chance of flipping the lines, and it would at least prove the Jags are CAN-capable.

Then the next step would be to take one Jag and connect to the RIO and see if that works. If not then it's likely cabling between the simple wires and the rj11.

[Jefferson]

We originally checked the colors and found them to be correct but we just swapped the wires and it caused us to lose communications to the PCM and the PDP which we had before.

You swapped the wires on the cables at the roboRio and at the PCM on the cable back to the Jaguar? You wouldn't have needed to change anything on the cable between the PCM and PDP.


The thing about the situation that confuses me the most is we still have comms to the PCM and the PDP while the wires are hooked into the jags but it is almost like the roborio is ignoring them entirely.

See Omar's diagram. I definitely think that's what has happened. It happened to us at least twice during alpha/beta. This can happen becuase the Jaguars will pass the signal through even if they aren't able to communicate on the bus.

[w8jrt]

We are also having the same issue. We have the pcm and pdp at each end of the network with the jags in the middle. You can see the pcm and pdp but no jags. If you break the network the pdp shows a stale data message on the web browser. Connect it back up and refresh and it's happy again. If you check the box for lighting the light you can see the effect on the pcm and pdp so i know comm is good over the network. Maybe we have the the high/low on the drives crossed? Am I safe in assuming that software in the robo rio is not the problem? Thanks.

[Tyler Scheuble]

When you flipped did you see the Jags in the roboRIO web-page config?
When we flipped the wiring we saw nothing on the roboRIO web page. Not even the PCM or the PDP.
Anyway it really shouldn't be this difficult. At this point I would just connect the RIO to one Jag only and get that working. Are these out-of-the-box Jags? Where they ever used before? If so were they working on can or pwm?
We took 2 jags out of the robot we used very recently on an off season competition, but we took a new jaguar out of the box and after rewiring we got the same results.
We have not tried PWM
When you connected with BDC-COMM was it over serial or CAN? I mean if you BDC-COMM (rs232) to one Jag, can you discover the second Jag over CAN?
BDC-COMM worked directly with a CAN cable to serial rs232 port directly into an older computer. We haven't tried connecting multiple jags over CAN but I don't see why we wouldn't be able to since that is how we successfully flashed them last year.

You swapped the wires on the cables at the roboRio and at the PCM on the cable back to the Jaguar? You wouldn't have needed to change anything on the cable between the PCM and PDP.
The wires we swapped were in between the Jaguar and the roboRIO itself. The wires themselves are direct and do not directly connect to the PCM.

[ozrien]

So I tried a fresh setup with a RIO, out-of-box Jag, and a PDP. Seemed to work.

I took a single RJ11 cable (2 wire red/green) and snipped it in two. Giving me two harnesses each with a RJ11 end and two bare wires (red and green).

One harness connects RIO(Red/green) to Jag(rj11) and the other harness connects Jag(rj11) to PDP(green/red).

What's tricky is that red and green are flipped between the two rj11s. As a result red/green is CANH/CANL on one and red/green is CANL/CANH on the other. The attached image better explains this.

So if you're cutting regular rj11 cables in half, be aware that the colors are not consistent on both sides of the Jag bus.

[Tyler Scheuble]

Your last post helped us fix the problem. Thanks for the solution!

We really appreciate how much time you have spent in helping us.

[ozrien]

Awesome! No prob.

Hmmm...maybe we should add that tip to the FRC screen-steps page.