HOW TO USE HOST COMPUTER VI TO CONTROL COMPACTRIO DIGITAL OUTPUTS

[suni]

Hi,
I am designing a closed loop control system using Labview FPGA  and  CompactRio real time target.  I am using FPGA for the control system coding. I want to use the host computer to monitor some signal levels and send out a signal using NI9401 module to control external amplifier. The host computer does not have memory capacity to hold labview software. Can I use executable on this host computer so I can have this front panel to monitor the control system? Could you tell me how to monitor signal levels going in and coming out from FPGA (is there sample vi I can look to get an idea? I am using Ethernet cable to connect compactrio to host computer ) Thanks!

[MikeS81]

Hi suni,

if you work with LabVIEW 8.6, then you can use the scan engine to get the values from your fpga to the real time target. If you do so, then you only need to work with shared variables. To see all your values on your host pc, you can create an executable which can read and write values over tcp/ip. There are a lot of examples about it, use the example finder please. To use the scan engine is only one way, you can write all the communication by yourself. For the communication between real time and host, i would use tcp/ip instead of shared variables.

Mike

[suni]

Hi Mike,

Thanks for your reply. I don't have any experience with CompactRio. Could you tell me If I use TCP/IP to communicate between compactrio and host computer, am I going to able to write to NI 9403(digital I/O) module that is connected to compactrio?. If that is possible could you tell how I can do this?  Also to monitor values in the FPGA using host computer first I need to get those values to compactrio real time target. If that is right could you tell me how I can do it? Thanks!

[MikeS81]

Hi suni,

which LabVIEW version do you use? Do you know the scan engine? To see how you can communicate over TCP/IP, use the example finder and search for tcpip.

Mike

[suni]

Hi Mike,

Thanks for your reply. I am using Labview 8.6. Sorry I don't know about scan engine. I will try to look for example and see. If I want to control and monitor signal levels in the FPGA code using host computer vi I need to use scan engine right. Thanks very much for your help.

[MikeS81]

Hi suni,

you don't need the scan engine, but with it you can use your I/O's without programming the FPGA. With the scan engine you have shared variables for all you I/O's. With the scan engine you only need to program the RT and the Host part.

Hope it helps.

Mike

[tom_z]

Hi Mike,

    You mentioned "For the communication between real time and host, i would use tcp/ip instead of shared variables.". Could you explain what is the reason for that, speed?

    Tom

[MikeS81]

Hi Tom,

for me it's not the speed. I only want to know how my program works and when a connection is established. 🙂

See this link for more information about speed.

Mike