NI Week Athena Announcement and Q&A Panel
 

Links here: https://decibel.ni.com/content/commu...mpetitions/frc

Announcement keynote at 9:30a ET/8:30a CT/6:30a PT, Panel at Noon ET/11:00a CT/9:00a PT.

Post all discussion/reactions here.

Re: NI Week Athena Announcement and Q&A Panel
 

Live stream just went up with 15 mins to go. Hall looks to be filling up fast.

Update: 5 minutes!

Update 2: Away we go!

Re: NI Week Athena Announcement and Q&A Panel
 

We have to WUB HARDER to reach these kids!

That jab at Java :rolleyes:

Re: NI Week Athena Announcement and Q&A Panel
 

NI said that Java was an arcane language, and was part of the problem with current education is that students learn it, yet they are going to be announcing a controller that will probably work with Java.:rolleyes:
There's a feature to zoom in the NXT programming language, but STILL NO ZOOM IN LABVIEW

Re: NI Week Athena Announcement and Q&A Panel
 

Your robot always fails when it matters the most! (Pesky radio!)

Re: NI Week Athena Announcement and Q&A Panel
 

Name is "roboRIO"

ARM Cortex A9 with 500% faster CPU.

50% smaller, 75% lighter.

ESD and shock safe. Overvoltage protection throughout.

Same APIs and programming language support.

Will donate one to each team

More details in breakout.

Re: NI Week Athena Announcement and Q&A Panel
 

Ooooh

Re: NI Week Athena Announcement and Q&A Panel
 

Best part: Every team gets one free! :D

Re: NI Week Athena Announcement and Q&A Panel
 

Can't edit the thread title. :mad:

Re: NI Week Athena Announcement and Q&A Panel
 

10 dedicated pwm, 10 shared
10 dedicated dio, 16 shared
4 total relay (that's not enough!!)
8 analog in
2 analog out
2 USB host
1 USB device
Ethernet, CAN, integrated accelerometer
Signal Light
Runs linux
256 MB Storage
256 MB RAM
667MHz Dual Corm ARM cortex A9

Re: NI Week Athena Announcement and Q&A Panel
 

No more SideCar? I love it ^^
I wish I was two years younger, I bet using this will be fantastic.

EDIT: woo post 300.

Re: NI Week Athena Announcement and Q&A Panel
 

Re: NI Week Athena Announcement and Q&A Panel
 

5.7 in. x 5.6 in.

Under 12 oz.

Wow.

Re: NI Week Athena Announcement and Q&A Panel
 

I bet this thing is <$250 as well.

Re: NI Week Athena Announcement and Q&A Panel
 

Most important questions for me:

Cost? For those of us that run 2 robots how much is this going to set us back?

Availability of both hardware and software? I don't like getting a new system on kickoff, and shipping it to me early December doesn't help much either.

Yes, I know it's over a year and a half out but it's never too early to make a plan of attack for utilizing new technology.

Re: NI Week Athena Announcement and Q&A Panel
 

-I agree with those thoughts on Java. Nothing against Java as a language, but IMO every introduction to programming I've seen for students that works in Java primarily teaches the concepts of object-oriented programming and Java syntax before actual programming concepts in general. I don't think OO is the only way to program, and a class that starts and only touches Java will promote a much more closed way of thinking about programming

-Every day I work in Simulink, I'm like 'man this is a big subsystem, I should zoom in' and then I zoom in. And then later I zoom out. AND THEN I GO BACK TO LABVIEW AND CANT ZOOM.



@everyone, Thoughts on the new controller:
-I think the expansion port is great for packaging, and allows plenty of additional IO, but I think it's going to be JUST that - a place where you can plug in a break out board to use the additional PWM/GPIO/ADC signals when you need them. I don't think more than a few teams will actually make something else for this port. Maybe a company or two, but basically no teams.
--I'm not worried about enough IO, but a few more ADC's would be nice for extra datalogging. Buzz18 uses 5 of 7 and Buzz 17 used 6 of 7, and it's nice to look at other analog signals every now and then. I also wonder if the 5v/3.3v supply is monitored by the ADC separately because we like to look at that for diagnostics, and previously used a jumper in adc7 to do this, which consumes an analog channel.

-The spec lists integrated 3-axis accelerometer. I wonder why they didn't include a gyro on this, since a gyro is definitely a way more useful sensor for FRC. I have never found a use for a chassis-mounted accelerometer in FRC.

-No spec on boot times as far as I can tell. Dissappointing. The radio issue demonstrated by 2468 almost made a joke out of the current boot times.

-OS is listed as RT Linux, which will definitely make some people very happy, but I don't really care that much. I still think we're brute-forcing the CPU loading issues rather than considering efficient design in quite a few places (outside of user code).

-Hopefully the download times improved. They were just purely awful this year. I know that was because of a LV RT bug, but it's still totally unacceptable in every way that it made it past testing like that.

-Maybe if I can get one early enough it'll push me to design something better. Who knows. But releasing software on kickoff is just crazy, I mean we really do have to install LV and new Driver Station and new Utilities on a whole bunch of computers, and there isn't even anything game related in a new version of software. I too would like to see the new controller and software in my hand at least 6mos before 2015 kickoff.

Re: NI Week Athena Announcement and Q&A Panel
 

My thoughts exactly. For the past three years we've been using more than 8 channels for pneumatic components.
The only hope is for the additional "Pneumatic" channels eluded to on page 3 of this document.
Will CAN save us all?

Re: NI Week Athena Announcement and Q&A Panel
 

If they're giving one to each team any team with a crio already (anyone who was a 2014 or earlier rookie team) will have both a roboRio and crio.

Re: NI Week Athena Announcement and Q&A Panel
 

Here are my thoughts on your concerns:

This thing is going to be cheaper than the cRIO. A current dev board (here) with a quad core ARM is $180. The plastic case and added pins doesn't add much to the cost. I would expect this to be priced under $250, but $300 would not be too far-fetched if I missed some components. I would be highly disappointed if this was anywhere close to the current $525 for the present cRIO.

LabVIEW won't change much between now and then. The target device may have some different setup requirements in the code (header files, target device settings). I would be surprised if the workflow was any different. The target device shouldn't matter much when it comes to the code - the compiler will do the work for you. The current cRIO is running a Real Time Operating System (RTOS) and I expect the roboRIO to also run a RTOS variant of Linux.

I am curious if NI will support the present cRIOs to allow us to continue to use them in the future for various other projects/classroom activities since we have four of them.

Re: NI Week Athena Announcement and Q&A Panel
 

Sounds like a great question for Friday with Frank or the Q&A later today.

Cross the Road Electronics is also going to have a CAN pneumatic device that will take care of the Compressor, Pressure Switch and 8 solenoids (12v OR 24v not both).

http://i.imgur.com/276hmyB.jpg

Pneumatic Controller from IRI 2013

-Clinton-

Re: NI Week Athena Announcement and Q&A Panel
 

A gyro would have trouble if a team decided to mount their control system vertically, or if they didn't put the controller in the center of the robot. Every year we get these accelerometers in the KoP, and I still have no idea what to do with them. We have like 10.

Also, I feel like the 500% increase in processing power was a bit unnecessary, but it's going to be cool to work with a dual core ARM Cortex processor.

Looking at the spec sheet, we can now use both ethernet and USB connected cameras, but their is no use listed for the USB device port.

Some questions:
-Do we have a jumper for the 6V servo power?
-The spec sheet lists specs for both a 5V and 3.3V supplies. Where are they, and can we use them? The old DSC had two extra pins for the 5V supply next to the DIO, but I don't see a way to get 5V from here without using one +5 pins on a DIO.
-How do we know which of the pins in the "custom electronics" connector do which things?
-The picture of the pcb shows a 5V/3.3V selection jumper, but it can't be seen from the new pictures. What does this select?

Re: NI Week Athena Announcement and Q&A Panel
 

There aren't any jumper ports... I hope we won't need a separate board for them.

Re: NI Week Athena Announcement and Q&A Panel
 

USB Host + ARM processing power... Definitely not unnecessary. Now you can hook your Kinect directly to the robot controller and do image processing.

Re: NI Week Athena Announcement and Q&A Panel
 

This is not good. The eight solenoid control really only allows for 4 solenoids, as the double solenoids require two channels to operate. With the relays it will allow for a total of 8 double solenoids. I know that 118 has used more than this in the past, and 236's bump thing used 8 just for their wheels, plus 2 or 3 more on the rest of the bot.

Re: NI Week Athena Announcement and Q&A Panel
 

If you can get the library to process kinect data on the controller, and if you can find a USB driver that works with linux on whatever USB controller is being used.

Re: NI Week Athena Announcement and Q&A Panel
 

http://new.livestream.com/accounts/4...mages/26730317

Just posted a new pic of the controller.

Re: NI Week Athena Announcement and Q&A Panel
 

As the device runs on CAN, I would assume you can utilize more than one of the devices on the robot at a time. From what I've seen inspecting, a majority of teams don't need more than 4 double solenoids. Since you have to draw the line somewhere (4, 8, 20, whatever), why not keep the whole thing as small as possible while making it all most teams need? The teams that need more will get more by adding more boards.

Re: NI Week Athena Announcement and Q&A Panel
 

Can you elaborate? Every rookie?

Re: NI Week Athena Announcement and Q&A Panel
 

Every team that'll sign up to the 2015 season, according to earlier announcements.

Re: NI Week Athena Announcement and Q&A Panel
 

I expect that the cRio will not be considered part of the legal control system starting in 2015. That doesn't stop you from using it on a practice bot, just like teams used the old IFI control system for non-competition robots after the cRio came out.

Re: NI Week Athena Announcement and Q&A Panel
 

What Jon said +1.

Also, teams can use single acting Solenoids and reduce the number of outputs needed. As long as they are comfortable with having a default state of their cylinder, that will actuate at the end of the match or loss of comms.

The CTRE device is replacing the current solenoid module that has 8 outputs, but allows for easier (and less weight) expansion of more outputs.

-Clinton-

Re: NI Week Athena Announcement and Q&A Panel
 

There are 3 axis gyros as well. I used a digital I2C one in my senior design project. The chip (L3GD20) had a footprint of about 4mm x 4mm, wonder if they can fit one on in future revisions?

Re: NI Week Athena Announcement and Q&A Panel
 

The specs list 8 ADC and 2 DAC. Presumably, the extra ones are on the Custom Electronics Port. Since the ADCs are 12 bit 0-5v, we get 2 free bits compared to the current cRIO, as long as you don't care about -10 to 10v.

Re: NI Week Athena Announcement and Q&A Panel
 

The relay outputs onboard are intended to drive a spike I imagine, if they are keeping with the nomenclature of the sidecar (and the fact that they are three pins confirms this).

Driving pneumatics off a spike is doable, but really doesn't make any sense in this era.

The CAN based pneumatics bumper would presumably allow effectively unlimited for FRC sake.

Also, no way 236 used more than 8 solenoids for that motion. I just don't see enough going on for that.

Re: NI Week Athena Announcement and Q&A Panel
 

how does one use livestream. i made an account and went to the link provided but there isn't a video feed, just a few posts with pics of the new controller. it says there are 300+ watching but i can't find it!! please an old guy out :-)

Re: NI Week Athena Announcement and Q&A Panel
 

Nothing is streaming yet(well, not until <2 minutes from now)

EDIT: As I typed that, the stream started, albeit with a lost signal message(That went away as I edited this post...)

Re: NI Week Athena Announcement and Q&A Panel
 

NM! it starts on its own...

Re: NI Week Athena Announcement and Q&A Panel
 

Anyone know when the video from this morning will be posted?

Re: NI Week Athena Announcement and Q&A Panel
 

Refresh, they just posted the stream.

Re: NI Week Athena Announcement and Q&A Panel
 

Q&A Starting!

Re: NI Week Athena Announcement and Q&A Panel
 

From the Q&A, there will be an expansion port for your own electronics/more analog inputs.

Re: NI Week Athena Announcement and Q&A Panel
 

Re: NI Week Athena Announcement and Q&A Panel
 

Kate won't say whether the roboRIO is even allowed for 2015. :yikes:

Re: NI Week Athena Announcement and Q&A Panel
 

Java SE! Java SE! Java SE!

Re: NI Week Athena Announcement and Q&A Panel
 

We will use Java SE, not ME, and we'll be programming in eclipse!

Re: NI Week Athena Announcement and Q&A Panel
 

Will be available for purchase in fall of 2014, beta testing next summer, info will be revealed in Frank's FRC Blog

Can be mounted safely via zipties

Re: NI Week Athena Announcement and Q&A Panel
 

You can continue to use Ethernet cameras, use simple USB cameras, or load your own Linux drivers to use virtually any USB camera.

Re: NI Week Athena Announcement and Q&A Panel
 

Can buy them fall 2014!

Re: NI Week Athena Announcement and Q&A Panel
 

You can attach it with cable ties!!!!!!!!!!

Re: NI Week Athena Announcement and Q&A Panel
 

Glad I wasn't wrong on RT Linux! RobotPy will essentially be obsoleted by this, as there will no longer need to be a custom Python interpreter (just need to wrap the new WPILib), plus we get all the rest of the goodies that come with Linux (shell access!).

It should be more than powerful enough to talk to the Kinect, at least at low resolution. Linux support is actually pretty good, at least if you're just pulling the image+depth field.

Re: NI Week Athena Announcement and Q&A Panel
 

Team cost: "Low $400's" to start. Always working to reduce cost.

Don't forget every team gets one for free. This is just for teams that want an additional controller.

Re: NI Week Athena Announcement and Q&A Panel
 

I'm going to love playing around with the RT Linux on this thing. Custom drivers can be loaded to have any device working with the controller!

Re: NI Week Athena Announcement and Q&A Panel
 

When the roboRIO is put into place, "legacy hardware" will no longer be legal

Re: NI Week Athena Announcement and Q&A Panel
 

This isn't the "FRC And Purchase Orders" panel, people :'(

Re: NI Week Athena Announcement and Q&A Panel
 

Not surprising, since every team gets a roboRIO for free.

Re: NI Week Athena Announcement and Q&A Panel
 

New PD board.

Re: NI Week Athena Announcement and Q&A Panel
 

Faster encoder and SPI sampling

Re: NI Week Athena Announcement and Q&A Panel
 

That's not awful. Definitely higher than I was hoping. What are they "adding on"?

Re: NI Week Athena Announcement and Q&A Panel
 

Recouping dev costs most likely. The CRIO was more or less an off the shelf part with a new screen print. This seems to be a custom built solution for some very specific needs with a small market.

Re: NI Week Athena Announcement and Q&A Panel
 

Not waterproof! :rolleyes: (But conformal coated)

Re: NI Week Athena Announcement and Q&A Panel
 

I agree with the development costs. They are producing a minimum of 6000 units if I remember the RFP correctly.

Have you seen the new cRIO they just released this week (cRIO-9068)? It's also an ARM Cortex A9 with a RT Linux. It should be pretty interesting to see how that is applied.

Re: NI Week Athena Announcement and Q&A Panel
 

Zynq-7020 information...

http://www.xilinx.com/products/silic...7000/index.htm
http://www.xilinx.com/applications/b...t/cameras.html :cool:

Re: NI Week Athena Announcement and Q&A Panel
 

All cool stuff, but am I the only one disappointed that the code name wasn't carried over to the final product?

Athena is just cool.

Re: NI Week Athena Announcement and Q&A Panel
 

At work and can't view the stream, but the comments here make it sound incredible. Electronics just got so much easier. Maybe with this and CAN Talons we'll give CAN another shot.

Re: NI Week Athena Announcement and Q&A Panel
 

Amen to that. CAN should be much better documented and supported come the 2015 season.

Oh, and I'm sure the name "Athena" will stick around for a while.

Re: NI Week Athena Announcement and Q&A Panel
 

Ohhhhhhhhhhhhhh man. I'm so jealous. Everything about this controller is better than the cRIO sidecar duo. I too liked "Athena" better than roboRIO, so I'll probably refer to it as the Athena for a little while longer.

Is there any more information available on the custom electronics port? pinout? This custom electronics port is the coolest feature of the Athena IMO.

I'm hyped and I'm not even a student anymore.

Re: NI Week Athena Announcement and Q&A Panel
 

During the Q&A, they referred to the custom electronics port as MXP (myRIO Extension Ports). NI's other product with an MXP has its pinout shown here:
http://zone.ni.com/reference/en-XX/h...ector_pinouts/

The point counts match the features of the custom electronics port, however I have no confirmation that this is the correct pinout diagram for Athena.

Re: NI Week Athena Announcement and Q&A Panel
 

FPGA?

Re: NI Week Athena Announcement and Q&A Panel
 

Haha, as one of the students on stage operating the robot, I can tell you that it wasn't actually the radio's fault. Our computer opened up some bizarre program that I didn't know how to close so space bar was my first reaction, which, as you know, is the E-Stop. This meant that I had to power-cycle the robot and wait for the cRIO reboot. Whoops. :yikes:

Re: NI Week Athena Announcement and Q&A Panel
 

It uses a Xilinx Zynq-7020, which is an Dual Core Cortex A9 ARM processor and Artix 7 FPGA in one package.

Joe Hershberger mentioned that encoder decoding was increased to 1mhz.

Re: NI Week Athena Announcement and Q&A Panel
 

This is very exciting. The NiWeek expo was incredible and the roborio is impressive. We talked with Greg and Joe, and they presented a neat option. With the USB available you can even use a small USB dongle as your robot radio.

Re: NI Week Athena Announcement and Q&A Panel
 

It does look very cool, I'm excited about the use of RT-Linux, that opens up lots of possibilities. I like that there is basic direct connections but also that there is expansion capabilities. Having SPI and I2C interfaces gives lots and lots sensor options.

And just think, add a small solid state drive and vBulletin, it can be your team's webserver in the off season :rolleyes:

Re: NI Week Athena Announcement and Q&A Panel
 

Both the keynote and the panel have been posted.

Re: NI Week Athena Announcement and Q&A Panel
 

I guess I'm dumb and not seeing the keynote, mind linking it?

Thanks.

Re: NI Week Athena Announcement and Q&A Panel
 

Re: NI Week Athena Announcement and Q&A Panel
 

The Zynq Chipset is a combined ARM Cortex A9 dual core and FPGA. Pretty cool if you ask me! I posted the links in one of my last posts, but here is the Zynq page: http://www.xilinx.com/products/silic...7000/index.htm

Re: NI Week Athena Announcement and Q&A Panel
 

Confused on servo power, due to lack of jumpers and everything. Is it software defined some how? Or will we need a separate board to run servos?

Re: NI Week Athena Announcement and Q&A Panel
 

It's definitely unclear. Specs 6V servo power so I guess it's software controlled.

Re: NI Week Athena Announcement and Q&A Panel
 

Can anyone identify the connector being used for CAN bus? It almost looks like it only has two pins.. where are the +5V and ground pins?

Re: NI Week Athena Announcement and Q&A Panel
 

FRC speed controllers don't connect the power pin to anything, odds are that they just routed 6v to the power pin on all of the PWM pins.

The CAN connector looks a lot like the power connector on the 2CAN. Probably just the two wires. As a differential bus CAN shouldn't need the 5V and GND being passed around.

Re: NI Week Athena Announcement and Q&A Panel
 

Correct. PWM power pins are 6V, and you get a couple of amps for driving servos.

Correct as well - the CAN topology in this system does not distribute power. Power would be supplied to each device separately.

Re: NI Week Athena Announcement and Q&A Panel
 

I'd assume that those two connectors are for the CAN-high and CAN-low wires. Power is probably separate since all the power systems on an FRC robot are separate from the controls.
What will likely happen is all of CTRE's new CAN stuff will have those two CAN ports separate from the regular old 12v power inputs on all the other components.

Re: NI Week Athena Announcement and Q&A Panel
 

i wish they had gotten a better toaster to record the webcast. I sincerely hope that the roborio can process better video quality than the webcast.

Joking aside, it looks great! I really like the smaller footprint, the lighter weight, and the canbus support. Do i see an optical port at the top next to the USB? would that be for faster camera response, or is it some other connector for something.

Re: NI Week Athena Announcement and Q&A Panel
 

Are you talking about the USB B connector? (To the left of the 2 USB A connectors)

Re: NI Week Athena Announcement and Q&A Panel
 

Oh, its a USB B, that's what it is. i was thinking it looked like the optical audio port and i was wondering what it would be for.

Re: NI Week Athena Announcement and Q&A Panel
 

I believe Greg mentioned that the USB B port could be used to drop programs into the roboRIO.

Re: NI Week Athena Announcement and Q&A Panel
 

I'm pretty happy about that detail.

Re: NI Week Athena Announcement and Q&A Panel
 

For robustness some systems pass around the control power. In these systems, the CAN bus control logic on each component is powered from the CAN bus power lines instead of the mains supply, ensuring the component is always reachable even if the mains supply to that component is lost (with optoisolation between the CAN control logic and the rest of the circuitry). This could be useful even in the FRC world: for example, tripping a breaker would not cause that CAN bus component (e.g. motor controller) to drop off the bus (so you could still pull status, and it could report it doesn't have mains power etc).

There is a serious problem with the current CAN layer where timeouts to Jaguars could swamp other parts of the system due to error spamming. As timeouts can be caused for multiple reasons (bad termination, disconnected cable, etc), regardless of the power distribution approach, my hope is that the software layer will be updated to avoid this issue.

Re: NI Week Athena Announcement and Q&A Panel
 

Note the new PDB is CAN enabled so it can report a tripped breaker as well as the current flowing through each breaker. So you will be able to tell if something on the BUS isn't responding due to a tripped/cycling breaker.

Re: NI Week Athena Announcement and Q&A Panel
 

EDIT: There is a hardware connection within the Jags to prevent this (see posts following)

The current Jaguar CAN has us daisy-chaining network nodes, so if one drops the network, everything beyond it becomes unreachable.

In the automotive world, (most) CAN Buses have a star architecture, everyone hears everything, always.

Re: NI Week Athena Announcement and Q&A Panel
 

I'm pretty sure this isn't true.

I can't find the schematics or pictures of the PCB to support this, but if I remember correctly, the CAN traces are bridged ON THE PCB of each jaguar. That means a jag without power will passively relay CAN communications through itself. This is true for CAN communications on all the jaguars. It doesn't apply to a black jag which is being used as a serial bridge. If that one loses power/communications... then you lose your conduit through which to communicate to the CAN bus. There's no way around that besides using something like the 2CAN.

I believe the softrware side of the house (for Java at least) doesn't handle a controller going off line gracefully. There's a timeout period of something like 3 seconds which the CAN communication code will block on. So this will effectively take down all CAN communications for that period unless YOU set your program up to detect the missing CAN devices and stop trying to communicate to them. 3 seconds of no communications to motor controllers doesn't make for a very happy robot. This is what happened to us in 2012 @ NYC during eliminations (with your team BTW). We had a snap action breaker which would randomly failing open for no apparent reason. This would take one of our drive train motor controllers off line, and cause the remaining CAN controllers to not get any communications for long periods of time(we had all our drivetrain motor comm.s in a single try/catch block). We were trying to fix this between Semi finals matches but by the time I realized what was causing our problem there was just not enough time to make the changes and deploy the code. Of course we didn't have that issue UNTIL semi-finals.

Re: NI Week Athena Announcement and Q&A Panel
 

This statement misleading.

The CAN signals are hard wired from connector to connector on the Jaguar PCB. Even if the Jaguar loses power, other Jags on the network will be unaffected.

However, if the CAN cabling is physically disconnected, then yes, every Jag after that will be unreachable.

Edit:
James beat me to it :)

He's also correct about the Black Jag when it is the serial bridge:

Re: NI Week Athena Announcement and Q&A Panel
 

I've seen references to RTLinux, and to Linux with "realtime extensions." Does anyone know what variant of realtime Linux will be on the RoboRIO? Have they revived RTLinux?

Re: NI Week Athena Announcement and Q&A Panel
 

It's a custom NI version. Per https://decibel.ni.com/content/message/56764 and http://www.ni.com/white-paper/14626/, it sounds like it's 2.6 with the PREEMPT_RT patchset (rt.wiki.kernel.org).

Re: NI Week Athena Announcement and Q&A Panel
 

Thank you -- I saw the whitepaper, but that didn't mention anything specific about the kernel itself. The NI community post is much more informative.

I'm glad to hear it's PREEMPT_RT -- in my experience with RTAI, Xenomai, and PREEMPT_RT, it has (by far) the best driver selection, being the only one able to use standard Linux drivers in realtime.

Re: NI Week Athena Announcement and Q&A Panel
 

I'm really happy about this. Having full linux onboard would be great. Access to the shell means we can write other programs, and have the main program call those programs, and it should allow us to get more modular. Also adding new languages should be possible just by wrapping the libraries, so C# and python will both be easily doable because both are available on Arm Linux.

Re: NI Week Athena Announcement and Q&A Panel
 

I'm guessing 3.2. http://article.gmane.org/gmane.linux.rt.user/10332

Re: NI Week Athena Announcement and Q&A Panel
 

Thanks otherguy and dyanoshak for the corrcetion. I was just plain wrong. Learn something new every day and all...

Yes, of course if you physically disconnect it, or if the 'Serial-to-CAN converter' (that first black Jag) goes down, all bets are off.

Re: NI Week Athena Announcement and Q&A Panel
 

If I recall correctly, the issue that some teams were having with CANbus was when one jag had some sort of error and flooded the CAN network with error messages so commands from the controller couldn't get through. I think it was just an issue with the jags.

Re: NI Week Athena Announcement and Q&A Panel
 

It's an issue with how WPILib deals, or doesn't deal rather, with a jag erroring out. If you keep trying to talk to the jag with messages that require an ACK you will have to keep waiting for the full timeout to not get one. Which will cause your code to slow down and throw motor safety errors which slow the code down further and...well you can see where this is going.

You can use the No-Ack versions of messages to help and/or add some intelligence in a class that wraps CAN Jag to prevent spamming messages to a jag that's not responding and to detect and re-initialize a jag that browns out if you are using anything other than the default mode.