topic Re: SCPI command check in LabVIEW

SCPI command check

vijay0507 — Mon, 06 Sep 2021 09:08:52 GMT

Dear NI community,

I am very new to LabView and SCPI commands. As part pf my work, I want to send SCPI commands in LV in order to communicate with Gaussmeter IGM11 to do the Magnet flux Measurement.

I read the IGM11 manual already to get the basic idea of the scpi commands. Using ethernet (LAN) I have established a connection between Gaussmeter and PC. Through RS-232 I need to send SCPI commands to communicate with the device. Using TCP I would like to communicate with the device. I have connect the labview to gaussmeter but its not showing any data values in the labview program. Even I have little doubt about the code, I dont know whether the code is correct or not. Could you please tell me the way I have implemented the code is right?!

and I need to get continuously data output when I place magnet on the sensor

Thanks

Vijay

Re: SCPI command check

GerdW — Mon, 06 Sep 2021 13:23:55 GMT

Hi vijay,

@vijay0507 wrote:

Using ethernet (LAN) I have established a connection between Gaussmeter and PC. Through RS-232 I need to send SCPI commands to communicate with the device. Using TCP I would like to communicate with the device. I have connect the labview to gaussmeter but its not showing any data values in the labview program. Even I have little doubt about the code, I dont know whether the code is correct or not. Could you please tell me the way I have implemented the code is right?!

and I need to get continuously data output when I place magnet on the sensor

Why do you need to send SCPI commands "through RS232" when you want to connect by LAN/Ethernet?
Do you get an error when the device "is not showing any data"?
To know if your code is "right" you need to read your device manual…
When you want to receive data "continuously" then your device needs to support that. Does it support a continuous data stream? What does the manual say about this topic?

Re: SCPI command check

crossrulz — Mon, 06 Sep 2021 14:07:51 GMT

Where are you connecting up to the instrument? And what are the commands you are sending?

Personally, I prefer using VISA for communicating with instruments. This allows me to switch between Ethernet, RS-232, GPIB, or USB and all that needs changing is the initialization. The API is similar to TCP, but more is handled behind the scenes for you.

Re: SCPI command check

vijay0507 — Thu, 16 Sep 2021 12:54:09 GMT

Hello,

I am new to LabVIEW and my questions would be obvious for some for you. So please help if you know the solution.

I am very new to LabView and SCPI commands. As part pf my work, I want to send SCPI commands in LV in order to communicate with Gaussmeter IGM11 to do the Magnet flux Measurement via RS-232 cable.

The rest of the project was going well except for the LabVIEW part because as I said earlier, I am new to LabVIEW.

I am using the “Basic Serial Write and Read.vi” provided in the NI examples folder. The problem is that I don't know how to modify the vi in order to receive continuously the data coming from the Gaussmeter.

Thus, the first question is:
1.) How to read continuously from the RS-232 port? (I tried to use 'while loop' but with no success, maybe I was doing it the wrong way.) If you know the solution, please help me with your ideas and suggestions.

2.) The commands which I am using are follows:

:read? Which read the data from gaussmeter
<STX>+0298.<ETX> transfer data every 100ms
:idnt? Identification Query
:rst? Reset command.

Please help me whether I am doing the correct way. Please let me know your suggestions

Thanks & Regards

Vijay

Re: SCPI command check

GerdW — Thu, 16 Sep 2021 13:00:45 GMT

Hi vijay,

@vijay0507 wrote:

1.) How to read continuously from the RS-232 port? (I tried to use 'while loop' but with no success, maybe I was doing it the wrong way.) If you know the solution, please help me with your ideas and suggestions.

To repeat a certain part of code "continuously" you should use a loop.

When you already tried to use a While loop and had no success, then you made something wrong…

Re: SCPI command check

vijay0507 — Thu, 16 Sep 2021 13:23:57 GMT

Hi GerdW,

Thank you so much for your reply. I couldn't figure out where the mistake is raising in the code. I was trying to read the data from the Gaussmeter IGM11 with RS-232 cable but not getting exact idea of the mistake. Can you please check the code once. Does my code can read continuously data with SCPI command "read". Please let me know your response.

Thanks

Vijay

Re: SCPI command check

Mark_Yedinak — Thu, 16 Sep 2021 13:37:44 GMT

In order to look at your code you need to post it. So far you only posted a screen show of a very small portion of your code That is not enough to work with.

Re: SCPI command check

GerdW — Thu, 16 Sep 2021 13:59:43 GMT

Hi Vijay,

as you can see from my signature line I still use LV2020, so you need to attach a downconverted version of your VI...

Re: SCPI command check

vijay0507 — Thu, 16 Sep 2021 14:02:49 GMT

Hello Mark,

I have posted my code in the previous message. For your reference attaching the code could you please check it. let me know your valuable suggestion.

Thanks

Vijay

Re: SCPI command check

Mark_Yedinak — Thu, 16 Sep 2021 16:20:13 GMT

Please save it for an earlier version of LabVIEW. I do not have LV 2021 installed.

Re: SCPI command check

santo_13 — Thu, 16 Sep 2021 16:25:26 GMT

Vijay, most of us don't just upgrade to the latest LV version for work reasons, you can assume that majority of the audience have at least LV2016 installed, if you share any VI in the latest version, they CANNOT open it.

I would recommend saving the VI in 2016 so that a larger audience can open and provide feedback.

Re: SCPI command check

vijay0507 — Mon, 20 Sep 2021 15:54:33 GMT

Hi,

Thank you so much for your reply. I am attaching my LV code of earlier version, could you please check and let me know your valuable suggestions on my code. Looking forward to hear from you soon.

Thanks

Vijay

Re: SCPI command check

santo_13 — Mon, 20 Sep 2021 19:35:42 GMT

Your implementation should be functional (implementation is simple enough for any VISA based read/write), the actual loop implementation could have been made efficient by using an event structure so that you don't perform read/write operations too frequently (some devices do not like that and may not keep up with providing replies).

Were you able to establish communication using Interactive VISA control? - https://zone.ni.com/reference/en-XX/help/370131S-01/ni-visa/interactivecontrolvisa/

Re: SCPI command check

vijay0507 — Tue, 21 Sep 2021 09:16:05 GMT

Hi,

Yes with the help of "NI MAX2" and "Interactive VISA control" trying to establish a communication between Gaussmeter and PC. I am concerning about the code. Could you please check code, will it be possible to read data continuously with SCPI command via RS232 with my code.

Thanks

Vijay

Re: SCPI command check

vijay0507 — Tue, 21 Sep 2021 09:16:34 GMT

Hi,

Yes with the help of "NI MAX" and "Interactive VISA control" trying to establish a communication between Gaussmeter and PC. I am concerning about the code. Could you please check code, will it be possible to read data continuously with SCPI command via RS232 with my code.

Thanks

Vijay

Not able to detect the device in NI Max

vijay0507 — Tue, 21 Sep 2021 14:07:37 GMT

Hi,

I am trying to establish a communication between gaussmeter and pc with RS232. I have installed the RS232 driver information (CD) on my PC. When I opened the NI max, its not detecting the device just its showing something has connecting but not the exact device. I have done NI troubleshoot for your reference I am attaching the figures. Could anyone please assist me regarding the NI MAX.

Thanks & Regards

Vijay

Re: Not able to detect the device in NI Max

GerdW — Tue, 21 Sep 2021 14:16:26 GMT

Hi vijay,

there is a "COM3" serial port shown in your MAX screenshot: this is all you need for your RS232 communication!

Re: Not able to detect the device in NI Max

santo_13 — Tue, 21 Sep 2021 14:16:49 GMT

Hi Vijay,

Looks like you opted to duplicate the topic on another board.

Anyway, RS232 shows up as COM port - that is good, beyond that, typically VISA tries *IDN? query to detect the instrument looks like the instrument did not respond back to that command.

Have you verified that the RS232 cabling or convertor you use is functional? Does your device come with any software to test with?

I would suspect that the TX and RX might have been swapped.

Re: Not able to detect the device in NI Max

RTSLVU — Tue, 21 Sep 2021 14:18:11 GMT

An instrument MUST BE IEEE488.2 compliant for NI-MAX to identify it.

Because NI-MAX uses the IEEE 488.2 common command #IDN? to identify instruments.

So your device will probably not show up anything but a Com port.

You can give your instrument a VISA Alias to make it "show up" as something you recognize in NI-Max and the VISA resource drop downs in LabVIEW

Re: Not able to detect the device in NI Max

vijay0507 — Tue, 05 Oct 2021 10:05:29 GMT

Hi Santhosh,

Thank you so much for your reply, I was trying to communicate directly with RS232 cable (Gaussmeter to PC). Since, I have read the Gaussmeter IGM11 manual, I got to know that I have to use Null modem cable for direction communication to computer. Actually, I was trying to communicate directly with RS232 cable without using Null modem cable. Does it the reason for not detecting the device.

"Could you please let me know do I need to use Null modem cable+RS232 cable"?

Yes, the device come up with software to test with Ethernet and US. It works and getting connected with those interface. I am concern about RS-232 cable since I have to send SCPI commands to read continuous data from the Gaussmeter so that's why I preferred to use VISA.

Could you please let me know your response. Looking forward to hear from you soon.

Thanks

Vijay