CAN to Ethernet

We have an application where we would like to convert CAN bus to Modbus TCP (Ethernet). To do this, our supplier gave us an ADAM RS232/422/485 to Ethernet converter, with the comment "this should work".
Has anyone here done a CAN to Ethernet conversion before using this type of equipment?
Or has anyone read from CAN bus using either RS 485, 422 or 232?

I just want to get an idea if this is possible, and roughly what is involved.

Thanks,

Doug

I believe what you need is a protocol converter. To Say Canbus does not mean much. It's like saying RS232. It defines wire and bit timings. Protocols that use Canbus are CanOPEN, DeviceNET and J1939 (maybe more...)

You need a device that knows how to take the data on the CAN side and map it to Modbus registers on the Modbus/TCP side and vice versa.

Something like this may be what you need: http://www.anybus.com/products/products.asp?PID=250&ProdType=Anybus X-gateway

If not, this company specializes in what you are looking for.

Have you looked into the Red Lion Controls Data Station Plus?
www.redlion.net
Its very cost effective... check to see if it works with your CANbus.

We had a need to go from CAN bus (specific protocol CAN Calibration Protocol) to EtherNET/IP (as IO device to ControlLogix processor). We used a NetBurner CB34Ex unit. One of our engineers wrote a CAN Calibration Protocol Driver (CCP), another wrote a offline configuration tool and we purchased an EtherNET/IP server driver from RealTime Automation (RTA) that was setup for use with the NetBurner module. They also have one for Modbus TCP. Their prices may seem high, but their code works as advertised. Of course the NetBurner is programed using C/C++ and uses a realtime OS based on Micro-C OS II. So it is solution I would think hard about before going that route, but as in our case we had no other choice.

Anyway, if this is something you are going to repeat you may want to look at something along these lines.

Otherwise the AnyBus and the RedLion product is something to consider if you are dealing with some of the more standard protocols over CAN (CANOpen, J1939, DeviceNet, etc.).


Oh, by the way, the ADAM 485 to Ethernet converter is not going to work unless you put a serial to CAN converter on the end of that and then write a protocol driver to convert the CAN messages that you want to send/receive from the Ethernet side. You need hardware to handle the low level CAN timings. This can be an embedded micro processor with the Bosch IP silicon embedded in it or an FPGA with the IP code from Bosch in it.

Anyway, with a little more info I might have a specific recommendation. What exactly are you trying to communicate with over CAN and do you know that the protocol and speed that you will be using?

Darren

Thankyou everyone for replying,

After checking through the exact Can bus protocol against your suggestions for a converter, I ended up convincing my client to not use CAN bus at all. This was going to be the only bit of CAN bus in the entire system, and none of us were familiar with how to use it.

Thanks again for your help,

Doug