C API for connecting to an expansion chassis

[rkjulfiker]

Is there any C API for connecting to an expansion chassis (like 9144) from a cRIO chassis (like 9068), over ethernet?

[ScotSalmon]

I asked around a little about this and apparently the answer is "sort of, but not really".

One answer I got was that you could write your own ECAT master stack in C. Probably not what you had in mind.

The only other way the 9144 can communicate with the outside world besides EtherCAT is by user-defined variables, pumped through RSI and the Scan Engine and then published to PSP.  So what you need for that is some C/C++ API to talk to PSP. Apparently CVI and/or Measurement Studio both have an API for this.  They call is "Variable API" or "Network Variable API" or "Shared Variable API" or something like that.  I've never used it, though.

Sorry not to have better ideas. If you come up with something promising, please post it!

[speleato]

Are you specifically interested in the 9144 EtherCAT chassis or would one of the Ethernet expansion chassis, like the 9149 meet your needs?

[rkjulfiker]

Any Ethernet Chassis could also work.

[speleato]

For Ethernet expansion chassis, you should be able to use the FPGA Interface C API to communicate with the remote FPGA from the cRIO target. I would recommend using the NI-9147 or NI-9149 and making sure that all targets have the same software version installed.

Message was edited by: speleato