Difference between normal CAN and 2CAN 2.0?

[GuyM142]

I can't find anywhere what is the difference between normal CAN and CAN using 2CAN 2.0, can you help me?

And btw, to update jags firmware do I need to use serial to USB adapter or there is a way to connect it to the ethernet port or even the VGA connection?

[otherguy]

Originally Posted by GuyM142

I can't find anywhere what is the difference between normal CAN and CAN using 2CAN 2.0, can you help me?

By "normal" CAN i'll assume you mean CAN using a black jaguar as a serial bridge.
In this configuration the cRIO communicates with the CAN bus (All the jags chained together with CAN cables) through the first black jaguar in the chain. What's happening is the cRIO and the first black jaguar are talking to one another over a RS232 serial connection. The hardware inside the first black jaguar then converts the serial commands into CAN data that is then sent on down the line.

The 2CAN on the other hand is a network device (ethernet) which talks to the jaguars directly over the CAN bus. The cRIO would send the 2CAN commands over the local network on the robot (through the wireless bridge).

Both systems will work. Using the black jaguar as a serial bridge will limit your bandwidth (the serial connection to the first jag is slower than the CAN bus). Using the black jaguar introduces a single point failure, if the first black jag dies or restarts, you can't ocmmunicate with any of the jaguars on the bus. With the 2CAN the single point failure is the 2CAN itself. If it dies, you can't talk to any of the devices on the bus.

And btw, to update jags firmware do I need to use serial to USB adapter or there is a way to connect it to the ethernet port or even the VGA connection?

Yes you need a serial connection. Some computers have the DB9 connector (serial port) that you need (look for older machines) if there aren't any computers with a serial port on them, you'll need to pick up a serial to usb adapter. Note that some of the super cheap ones off ebay won't work correctly under newer versions of windows. Make sure the hardware you're buying has support for the OS you intend to use it under.

Also, it's not a VGA connector, it's a similar shape, but there are fewer pins on the connector.

[GuyM142]

Thank you for the explanation,
If I'm going to use it only for two CIM motors (2 Jaguars) which are connected to the same gear box, I would better use the "normal" configuration, right?

[otherguy]

Both systems will work. Using the black jaguar as a serial bridge will limit your bandwidth (the serial connection to the first jag is slower than the CAN bus). Using the black jaguar introduces a single point failure, if the first black jag dies or restarts, you can't ocmmunicate with any of the jaguars on the bus. With the 2CAN the single point failure is the 2CAN itself. If it dies, you can't talk to any of the devices on the bus.

That said, I have a follow on question... If you're only going to use it for two motors on your robot, why not just use PWM cables?

Do you need to use one of the features of the Jag that's only available over CAN?

[GuyM142]

Originally Posted by otherguy

That said, I have a follow on question... If you're only going to use it for two motors on your robot, why not just use PWM cables?

Do you need to use one of the features of the Jag that's only available over CAN?

I will use the voltage control over CAN.