Problem using the "FRCH" vi library to convert to USB, FRAME-based, CAN

[Arnie1]

Has any one tried to use the FRCH vi library for converting a channel-based CAN communication application to Frame-based? Currently the application works well on the NI PCMCIA CAN cards but was hoping to transfer it to USB, using the NI-USB-8473, as this device is cheaper and may new laptops do not support PCMCIA cards.
I have had partial success, but the conversion VI, which creates the message table from the channel list does not seem to cope with lists of more than about 20 channels. The application requires around 100 channel names.

Thanks.

[DirkW]

If i understand this correctly, then you try to run your Channel db file on USB CAN and you are using the Frame to Channel conversion Library?

And the conversion VI does not work with more then 20 Channels?

What kind of error do you get? How does this 20 channel limit apply with your messages? Is there one message having 100 channels or do you have multiple messages with overall 100 channels?

Could you post your ncd file?

I tried a message with 28 channels and it worked as expected.

DirkW

[Arnie1]

Hello, Dirk,

Thank you for the reply. The application is for a development, control and monitoring panel for a pice of electronic hardware. I've since done more work on this and it seems that sometimes the number of channels picked up is 19, sometimes 20, sometimes 27, depending on whether I add them all to one message table or split them into two or three message tables on the same handle.

I don't have any error messages and the system seems to run except that when looking at the channels in the message table, they don't appear to be all there.

I am using a CANALYZER dbc file for the channel data. Typically, each message ID will contain data for two or three channels. The control panel being developped is for an aerospace application and consequently there are over 100 channels to be monitored.

At this point I'm not certain whether I'm perhaps doing something wrong because whilst there is a large table of read-only channels, the table of write channels is much smaller at about only 10 (going into a separate message table) and there are problems with this also. The data in the Write channels can be changed and I can see that the data in the CAN frame changes accoridngly, but the unit with which it communicates does not recognise the message, as if the constructed meaasge Frame is not completely correct. But I'm away from the system for the next few days, so I am presently unable to check it further.

Thanks

Arnie

[DirkW]

Hi,

I do not really understand what you are doing. Could you send your code an ncd db file to the following address?

canpse@ni.com

I could have a look to your code to see whats going on.

DirkW

[Arnie1]

Dirk, Thanks. I'll send you the files.