07-07-2020 06:50 PM
I'm working on set up a pump in lab and I want to use NI to control the pump. Our group have done it several years ago but all of them have graduated. So I can't get any help. What I have is PCIe-6321 on a new computer and a SCB-68A connected with pump for controlling and data acquisition. I'm sure the line connected should be right because I just followed what our group previously used. When I run the program, an error - 1073807339 occurred at VISA read. The possible reason is VISA: (Hex 0xBFFF015) Timeout expired before operation completed. As I used VISA interactive control by commend *IDN?\n, read operation error occurred. It is the same 0xBFFF015 Timeout error. I think the main possible reason is there is some errors between the connection of PCIe-6321 and SCB-68A. I have checked the line for several times but it didn't work. Does anyone have some suggestion on how to solve this problem? Thank you.
07-10-2020 05:53 PM
FYI, PCIe-6321 is a MFIO and uses DAQmx drivers. SCB-68A is just a breakout board for the 68pin VHDCI connector. You are trying to use a VISA read/write on ASRL1::INSTR - you've not mentioned if anything is connected over the COM port to do such VISA communication. And no, 6321 card does not respond to VISA API read/write command and also not to IDN? query. These are for SCPI based instruments connected over GPIB/Serial/LXI/RS232 protocols that are supported by VISA.
In case, you would need to control the pump, you need to know the signals required by the pump and write a program to generate those signals (just digital states or analog voltages or a protocol) on the PCIe-6321.
07-13-2020 04:17 PM
Hello Santhosh,
Thanks a lot for your reply. There are 5 connection with SCB-68A. One is the connect to PCIe-6321, the second one is to a pump commander (Emerson Industrial Automation, Commander SK) which connected the pump. Other three connection is to an actuator(Hanbay MCJ-050AB), a pressure sensor to get some data and the power supply (DC power supply PS-305D). That's all the hardware I have. Do you mean I lose something to do the VISA communication?
Also for the software. I used a LabView code from our group to control the pump while record the pressure from sensor as attached. The problem shown when I run the program is that error -1073807339 (VISA read error). That's the reason why I go back into VISA interactive control and found the problem. ASRL1::INSTR is the only device I found in VISA interactive control. So does it mean the connect line between SCB-68A and PCIe-6321 is broken? And how can I check whether the PCIe-6321 can read the data or not?
Thanks again,
Weiliang
07-13-2020 04:22 PM
Also on the ASRL1::INSTR, the attribute shows as the following picture. I wondering does this related to my problem?
07-19-2020 07:18 PM
Could you please share the NI MAX hardware tree snippet to understand the instruments available and their names?