Communicating through PIO

[hosa]

Hi,

I am using LabView 8.5 to control a device. The device has a PIO interface which is connected to a NI-PXI 6508 board whitin a PXI-1000B chassis. I am trying to communicate with the device, but can't.

Is there any tutorial that show me the procedure?

Thanks

[MilanR]

Hi hosa,

Are you having problems communicating with the PXI-1000B chassis and the PXI-6508 card or are you having problems communicating with the external device using the chassis? What is the device you are trying to communicate with and with what protocol?

[hosa]

Hi Milan,

The problem is the second. PXI chassis works fine. I don't know if the problem is with PXI 6508 or the external device. The external device is a digital piezo controller (PI E-710) with a PIO interface. I have connected the PIO interface to PXI-6508. I also used DAQmx to read from digital ports. But it is always a constant input.

Hosa

[MilanR]

Hi Hosa,

You can test if the PXI-6508 digital ports are working by connecting the +5 Volt pin to a digital port and seeing if a digital high is read and then connecting the ground to the port and seeing if a low is read. The PXI-6508 manual shows that both a +5 Volt pin and a ground pin are available to test against. This will help confirm whether or not the problem lies with the PXI-6508 or with the PI E-710 controller.

Alternatively, If the ultimate goal is to interface LabVIEW with the PI E-710 controller, it might be worth trying to use the GPIB or RS-232 Serial drivers that Physik Instruments mentions on the LabVIEW Driver for E-710 Digital Piezo Controller page. You may have to contact the company to receive the drivers as mentioned on the page, but it will make development much quicker to have a pre-built interface.

[hosa]

Hi Milan,

Thank you for helping me.

I have control over E-710 with RS232. It was easy. But, the goal is to have the same control, in labview, using PIO interface of E-710. This is the case I am unfamiliar with, and need some experience or documents. PIO interface provides fast monitoring of axes positions.

I contacted PI asking for up to date VI for use with PIO. They don't have a pre-buit interface that can be used for my purpose.

And I am going to test the digital port using your method.

BR

[GabrielaK]

Hello Hosa,

unfortunately, the E-710 is replaced by newer controllers for years now, so there is no update of the PIO samples planned. Have you found the PIO LabVIEW VIs on the E-710 CD (located under "Samples\LabVIEW\PIO")?

Regards,

Gabriela

[hosa]

Hello Gabriela,

Yes, I found the sample VIs. But they are not working with this version of LabVIEW 8.5.1 that I have. And, also I am using a PXI system, that is not supported by the VIs from PI. I mean that I requested an updated VIs from PI, and they provided me with new VIs that can be opened by version 8.5. However, they still have problem for reading and writing, because they are not DAQ compatible. 

Hosa

[MilanR]

Hi Hosa,

If you know how to communicate with the device over RS-232 (i.e. what data to write to the RS232 interface and how to parse responses), it is possible to use the same type of communication from LabVIEW. You can use the NI-VISA driver to interface with RS-232 ports that are available on your system. The VISA driver can be found at ni.com/drivers and the Developer Zone article called NI-VISA Overview has an explanation of VISA and a quick LabVIEW example.

[GabrielaK]

Hello Hosa,

just to comment on Milan R's message: for RS-232 you do not need to care for anything like VISA, as the GCS LabVIEW driver set does all communication with the controller internally (based on NI VISA). But I guess this was not your question, but you would like to use the PIO interface with DAQmx. This is, as you already found out, not supported (the PIO driver is based on the old DAQ functions). Sorry that I have no better answer for you at this time. If it was one of the current controllers like E-712 I could do something, but the E-710 has been discontinued for quite some time.

One suggestion would be to think over if you really need the PIO interface or if RS-232 would be sufficient for your application. This would save you a lot of work as for RS-232 everything is built-in into the GCS LabVIEW driver set.

Regards,

Gabriela

[hosa]

Hello Gabriela,

Thanks for you comments. Yes, it is not supported to use DAQmx with PIO interface.

If you have any experience on E-712, can I ask you some questions in the future?

hosa