Is it possible to control a GPIB instrument by the instrument through GPIB

I'm having a Function generator, it has an in built GPIB, I'm writing an application on oscilloscope which also as GPIB, I have connected the GPIB port of oscilloscope to the FG GPIB port. I tried to send a GPIB command from the oscilloscope to the function generator. I wanted to know whether it is possible to control an instrument from a instrument through GPIB.

The answer is yes and no. There are three categories of devices:
talker/listener
talker/listener/controller
talker/listener/controller/system controller
Most instruments are "talker/listen-only". All they can do is act like a device on the GPIB.
You do run across a few instruments that are "controllers' as well. These instruments can be passed control from the system controller to temporarily control the bus, perhaps to calibrate themselves with a collaborative instrument. To find out if your instrument supports this, you probably need to look in the instrument's user manual.
The other option is for the device to be a system controller. This means that the device can control the bus at bootup (system controller) and run a host-side API (i.e., NI-48
8.2) to control an instrument. This sounds like what you are interested in.
I hope this helps.

Similar Messages

[Help]How can I power on or power off the specpum through GPIB by VC6.0 ?

[Help]How can I power on or power off the specpum through GPIB by VC6.0 ?
[帮助]如何在VC6.0环境下通过GPIB卡开关频谱分析仪的电源？
For this is my first programme, thus ,I have no idea how to write code, and don't know the heaer files and DLL files to be included or imported.
因为这是我写的第一个程序，所以，不知道如何写代码，也不知道需要引用或者导入哪些头文件或者库文件。
Thank you ！
谢谢！

Your question is very abstract, and difficut to understand what you want to do. Do you wish to control your spectrum analyzer for TURN-ON and TURN-OFF power?
Assuming your question is so...
To turn the instrument power OFF, you should look for the GPIB command that can do this in the instrument's operation manual.
To turn the instrument power ON, it is very difficult or almost impossible to do so, because your app program will have no way to communicate with your "unpowered" instrument.

GPIB error in the instrument while no communication error

I am developing a test system by connecting several measurement instruments through GPIB with LabVIEW 6.i. The driver is written by using VISA command. GPIB control card is NI PCMCIA. When using laptop everything runs fine. When using an old PC with something like EISA to PCI converting card for slotting in the NI PCMCIA card. One instrument always displays an GPIB error. The error is instrument specific, no further detail is given by the manual. When the error comes out, no GPIB or VISA error exists. If only the driver for this instrument is installed so that the software only communicates with this particular instrument, no error. With other driver installed, there is no error in the first or two commnunication
. Later on the error is surely out and display in the instrument screen only. Once again, no any other GPIB or VISA communication error. Anybody can help on this ? Thanks a lot.

Hi JLS,
First of all, thank you very much for your prompt response. I am not sure some of your questions because our hardware engineer is away for a week. I am trying to explain what I know and see whether you could help to figure out the reason.
0. The operation system in the old PC is Win98. The CPU is PII 350MHz, 32G Hard disk and 320M RAM. The reason why we are using the old PC is that we have a 3rd party motion controller. Its control card is a ISA card.
1. The conversion device is a kind of card, put in the ISA slot in the PC extention I/O bus. We can slot in 2 PCMCIA cards in the conversion device. The driver for the NI PCMCIA card is supposed to be the same with that in laptop.
2. The driver that works with the instrument is developed by me by using NI-VISA. The instrument is a signal generator (SG) from Marconi instruments. Basically what the driver does is to turn on or turn off SG and read back its on-off status. When turning on SG, send setting frequency and signal level data as well. The calling of the driver is in a loop where frequency is stepping up.
3. There are other measuring instruments. e.g. electric field monitor probe to get the electric field strength etc. All these instruments' driver are developed by me by using NI-VISA. I also develop a set of dummy driver for all the instrument for demo purpose. Dummy drive did not communicate with instrument, inside, control is directly wired to status. When all other instruments except SG uses dummy driver, The running is OK. No error is displayed in the SG screen. If I use any of the other instrument's driver with that of SG, there is no problem at the first run (that means at the beginning of the loop), problem surely comes out later on. But it is OK when running in the laptop of which the OS is Win2000. The funny thing is if I takes out the status readback in SG driver, there will be no error at all even running with other instruments' driver in the old PC. I have compare through the GPIB card setting in the old PC and laptop, make sure that the EOI setting, primary address, EOS etc. to be the same in the two computer. It does not work.
4 & 5. The error displayed in the instrument screen is Error#403 "Data Expected". The manual said it is caused by the GPIB programming wrongly. No further explaination on how it may happen. Even there is such error display, no any GPIB or VISA error happens in my driver, the error cluster is clear. I debug the problem and find that the SG error appears when executing VISA resource open. I have also checked through all the NI GPIB help. It seems I could not find the answer.
6. I am not sure how to check the version of NI-488.2 and NI-VISA. NI-VISA is installed with the LabVIEW 6.i together.
Best Regards
Jason

Trigger&Gate Express VI. Is it possible to control Dialog Box parameters on the frontal panel?

When you use a Trigger&Gate Express VI the Dialog Box Options permits you to configure the VI. I am asking if it is possible to control Dialog Box parameters with controls on the Frontal Panel. I am especially interested on Start Level Threshold.

open the VI that the trigger and gate is in. Right click on the express VI and select open front panel. Then find the control that you want and edit the connector pane to be able to input the parameter that you want. Attached is a modified version that I came up with for you.
Hope this helps you.
Joe
Joe.
"NOTHING IS EVER EASY"
Attachments:
example_trigger_and_gate.llb ‏92 KB

NI MAX can't detect instrument but the instrument can be pinged

Hi,
I'm in the process of connecting a Lecroy oscilloscope to a cpu via a cross over cable with plans of controlling the scope through some VIs. I cannot get NI MAX to find the oscilloscope, even though I can ping it. Below are the steps I've taken:
1) Installed NI-VISA and VICPPassport along with all the appropiate Lecroy drivers for Labview
2) Configured the IP addresses of the scope and CPU and successfully pinged each other (no firewalls active, same subnet, connected with cross-over cable).
3) Installed Lecroy's wavestudio software, established succesful communication with the scope (it had no trouble finding it automatically)
4) Opened NI MAX and tried to auto detect the scope using create new TCP/IP option. Failed. Also, the manual option failed as well.
I don't understand why I can ping the insturment, and interact with it using wavestudio, but NI MAX can't find it.
Any ideas?
Thanks

Hello SimonWall,
The VICP pport (the rules of the post do not allow me to use the word p&$$port correctly) uses port 1861. The firmware on the TeledyneLeCroy scope will setup firewall rules to allow the LXI and the VICP connections. Typically, the issues with a block are either the fact that WaveStudio (or some other application) is still connected to the device when attempting the connection, anti-virus software that has been installed on the scope, or the scope has been connected to a company network that implements policies that have blocked it.
There is an app. note on the TeledyneLeCroy website that describes the VICPpport (and has the port information as well) that may help you: (Due to the rules of the community for posting here, I cannot add the link, but you can search on VICP from here) TeledyneLeCroy App Notes
I hope this helps!
Leonard Brown
Applications Engineer
TeledyneLeCroy

Best way to control and read data from multiple instruments?

Hello,
I'm building an application to test power supplies involving multiple pieces of equipment over a couple of different comm busses. The application will also send control instructions to some of the instruments, and read data from some of the instruments. The reading and control profiles will not run on the same schedule (variable length control steps, configurable read interval).
I was thinking of using a queued statemachine (producer/consumer) for the control profile and another to read the data, but I got concerned that there would be collisions between sending control commands and read commands to the same machine. Is there a suggested design pattern for implementing something like this?
Timing of the commands isn't critical down to the milisecond, but I need to collect reasonably accurate timestamps when the data is read. The same is true for the control commands.
Here are the instruments I'm going to use, if the are control, read, or both, and the communication method
Instrument Funtions Comm Method
Power Supply Read data Communicates to PMBus Adapter
PMBus to USB Adapter Read data USB (Non-Visa)
Switch control relays USB (VISA)
Power Dist. Unit read data/control outlets SNMP (Ethernet)
Electronic Load read data/control load GPIB (VISA)
Thermal Chamber read data/control temp Ethernet (VISA)
Thanks,
Simon

Hello, there is a template in LV called "Continuous measurement and Logging".
It can give you some idea how to properly decouple the "GUI Event handler" top loop (where your Event structure is) from the DAQ and other loops.
You do not need to totally replicate the above example, but you can find there nice tricks which can help you at certain points.
The second loop from the top is the "UI message loop". It handles the commands coming from the top loop, and regarding to the local state machine and other possible conditions and states, it can command the other loops below.
During normal run, the different instrument loops just do the data reading, but if you send a control command from the top loop to a certain instrument loop (use a separate Queue for every instrument loops), that loop will Dequeue the control command, execute it, and goes back to data reading mode (in data reading mode the loop Dequeu itself with a "data read" command automatically). In this way the control and data read modes happen in serial not in parallel which you want to avoid (but I think some instrument drivers can even handle parallel access, it will not happen in really parallel...).
In every instrument loop when you read a value, attach a TimeStamp to it, and send this timestamp/value couple to the DataLogging loop via a Queue. You can use a cluster including 3 items: Source(instrument)/timestamp/value. All the instrument loops can use the same "Data logging" Queue. In the Datalogging while loop, after Dequeue-ing, you can Unbundle the cluster and save the timestamp and data-value into the required channel (different channel for every instrument) of a TDMS file.
(Important: NEVER use 2 Event structures in the same top level "main" VI!)

Communicate by NI-GPIB card with an instrument that was designed especially for HP-GPIB

I have an instrument (Data Link Test Set by Apogee Labs) that has GPIB interface and a book of commands.
I have a NI-488.2 card and I try to send commands with the MAX. The device is identified but it respond to the commands by blinking its display and strange hex answer.
The manufacturer said they have no problem like that, but they tested their GPIB interface only with a HP card and not NI card. This is a big problem for me, because it's all part of a deal, and the customer want to have it with NI.
What possible solutions do I have in order to communicate this instrument with NI card, though it was designed only for HP card.

Hi Toti,
GPIB and HPIB are the same thing. They are different names for the IEE 488.2 communication standard. The 488.2 specification is an extension of 488.1 and it is backwards compatible. IEEE 488.2 uses the same electrical specs and low-level states machines. You are probably refering to IEEE 488.1 as HPIB.
IEEE 488.2 defines a set of required commands. MAX uses the ID query command *IDN? to retrieve the instrument ID string. With a non-488.2 compliant instrument the interface is capable of sending and receiving information to the device, but in the particular case of the MAX 'scan for instruments' option the instrument won't recognize the *IDN?. This is way you are getting a error message in the instrument. In MAX you are detecting the instrument
, but it says that it didn't respond to the *IDN? query.
To test the device, review the instrument's documentation and determine the ID query command (if any). It might be something like 'ID?'. Then use the MAX 'communicate with instrument' utility or the interactive control (ibic) to send the correct command to the instruments.
The botton line: you should be able to communicate with this instrument.
DiegoF
National Instruments.

ATE does not recognize other models of measuring instruments connected through GPIB

Hi,
I've a ATE (Automatic Test Equipment) which has many measuring instruments connected to it through GPIB. Recently one of the oscilloscope was not working & I tried to replace with a oscilloscope of different model, the ATE does not recognize the new instrument. As the only communication means is through GPIB, I presume that the issue is on GPIB connection. Is there any setting or configuration that I must do besides setting the GPIB address at the replacement oscilloscope?

It's also certainly possible that the ATE software was written for a specific make and mode of scope. It's two different things when the ATE software doesn't recognize the scope and when the gpib controller itself doesn't see it. Each make and model of scope will return a unique string when queried with the *IDN? command and it's common for ATE software to check this before proceeding and sometime different models of scopes from the same manufacturer will have different command sets. Do you have access to the software? Can you check what the ATE program is doing? Do what Uwe recomends first and if MAX finds the scope, I would suspect the ATE program.

In MAX, how do I release GPIB control of the instrument without restarting my scope?

n MAX, how do I release GPIB control of the instrument without restarting my scope(HP54120B)?

Hi,
I don't think I understand what you are asking.
If you are refering to the instrument's front panel, which locks when the instrument goes to remote mode, then it depends on the instrument how it can go back to local.
Some instruments will go to local by pressing any key, others a particular key. Refer to the instrument's documentation.
There is also a NI-488.2 function that makes the instrument go to local: ibloc.
Hope this helps.
DiegoF
National Instruments.

GPIB Polling of an Instrument Register

I have developed a VI using the event-driven producer-consumer template, and I am very happy with the performance. Now, I need to add another instrument to the system - a scope controlled over a GPIB interface. The scope control is easy and the drivers were readily available on the NI web site. Here's the problem: I need to set up the scope to acquire data with segmented memory - basically I need to capture x number of pulses, then I need the scope to tell the PC when it has all of the data. I can do this by reading a register in the scope and looking for a set bit. In a simple VI I have acomplished this and it works well, but it is also taking a lot of resources to do the polling. I am wondering if there is a way to set up a background poll that will interrupt the VI when a specific bit signature is obained, and do so without using a great deal of system resources. In the meantime, the VI can monitor and control the rest of the system. Has anyone come across anything like this before? Thanks!

smercurio_fc, thank you for the reply. I am intrigued by the idea of dynamic events, and I will look into it. In the "dummy VI" that I wrote to poll the register, I am using an uncontrolled while loop (no wait) to poll the scope register. Polling the register requires me to send out a query string over GPIB, wait for, and evaluate the reply. The part I am having trouble with is that I have to continue to send the polling command to the scope, wait for the reply, and evaluate the return in order to determine if the bit is set in the register. I envision a VI (that perhaps I can set up in a dedicated thread) and set to polling the scope register. Meanwhile, I can have the main VI controlling the remainder of the system. When the polling VI realizes that the register bit has changed, it will interrupt the main VI, which will then respond to the changed bit. I have looked into the scope control manual to determine if it can send a command over GPIB when the register bit is set, but it does not look like this is possible. I have to actively poll the register continually. Will dynamic events work in this scenario? Will parallel loops work in this scenario? Thanks again!

GPIB vi created with Instrument I/O assistant not timing out

I am new to Labview and I am trying to write a
program to control a HiPot tester via GPIB. This HiPot tester is used
on several other projects, so its GPIB address can vary. I want to use
Labview to scan for this device on the bus and then configure it.
I used the Instrument I/O Assistant to create a subVI that can query
the device for its manufacturer and model information. In this VI I
created some connectors that allow an outside program to input the bus
and device number. These numbers are formatted into a string and then
used to send commands to the GPIB device.
If I use this vi and specify the correct bus and device IDs for the
hipot tester, I get back the expected data. However if I send in the
wrong device ID (or wrong bus), the program hangs.
The Instrument I/O Assistant creates a timeout value of 2000 msec for
the operations. The *RST and *IDN? commands are sent first and then the
VI performs read operations to fill 128 bytes. So I figure that the
longest this should take to timeout is 2000*130 msec = 4.3 minutes. But
10 minutes later the VI is still running.
Why does this operation not timeout if the device and bus IDs on GPIB are not correct?
Brian Rose

Hi Brian
the first problem would appear to be that you send a reset command. But you only give the instrument
100ms to reset/reboot before your query its identify. If you have the instrument manual check to see actual timing
of bus etc.
As a rule of thumb I wait 300ms - If you run NI spy you will be able to see exactly when processes occur.
Add a sequence frame between reset command and id command.Place a
wait icon in the frame with a control on the input time so that you can
adjust time from front panel.
Initially set time to 400msand see what NI spy reveals.
Go for it
chow xseadog
Message Edited by xseadog on 09-10-2005 01:47 AM
Attachments:
wait.PNG ‏11 KB

Communicating between GPIB IEEE 488-1978 Instrument and LabView

Hi,
I'm currently trying to convert some old BBC BASIC Code into Labview 6.1.
The BBC Computer has a GPIB Comms Unit attached to it to communicate with an old Marconi Instruments Microwave Counter 2440 using GPIB IEEE 488-1978.
I am currently trying to get Labview to communicate with the Counter using GPIB 488 vis and a NI GPIB 488.2 Card but I'm not able to get anything out of the Counter or get MAX to even acknowledge the equipment exists.
I was wondering if anyone out there knows if it is possible to communicate with a GPIB IEEE 488-1978 instrument in Labview 6.1 (or any other LV Versions) and if it is, does anyone have a driver for the instrument (Marconi Instruments Microwave Counter 2440 circa 19
84) or having any helpful tips on the protocol for talking to a IEEE 488-1978 instrument.(I have some previous experience using VISA.)
Many Thanks in Advance for your help.
Sammy Mason

I have done this with several instruments. It is best to get a hold of the manual for this instrument and see what commands it uses.
MAX will not find this using the *IDN? query. In MAX, open the "Communicate With Instrument" window and type "ID?" (without the quotes), and hit query. You should get some basic information back from your instrument.
I use GPIB Read and GPIB Write most often. Your instrument probably doesn't support much else. Maybe Clear and Poll.
Be careful if you are using a newer, faster computer. There are Knowledge Bases and Discussion Forum topics that discuss the problems that can arise. To prevent these problems, I created my own Read and Write VIs. They just have a few milliseconds delay before the read or writ
e takes place
Attachments:
GPIB_Read_with_Delay.vi ‏37 KB
GPIB_Write_with_Delay.vi ‏35 KB

Need my computer to look like another instrument on the GPIB bus

I have a set of test instruments connected via a GPIB bus and controlled by a desktop computer with a 488 card in it. Into this scenario I now need to connect, to the 488 bus, another computer, a laptop. The laptop will NOT be a controller of any sort. The laptop must appear as another addressable instrument to the desktop controller. The laptop has only a USB interface through which I can talk on the 488 bus so. What type of USB to GPIB hardware do I need to do all of this?

Hello,
Yes, Jim's suggestion is right on, where once you have a GPIB interface for your laptop (via a USB-GPIB device) you will be able to pass controller in charge status to whichever interface you choose, and the other interfaces and instruments will appear as devices on the bus.
Repost if you have any other questions!
Best Regards,
JLS
Best,
JLS
Sixclear

Why can't the Instrument Wizard detect my GPIB instruments?

My system has the AT-GPIB/TNT card. I can detect the GPIB instrument connected to the card with "Measurement & Automation" but when I go into Labview Instrument Wizard and try to find the GPIG instrument, all I see is Serial ASRL1 and ASRL2. What can I change so that I can detect the GPIB instruments in Instrument Wizard? I've tried everything. I have NI 488.2 v1.60 installed and NI VISA v2.01. Any help would be appreciated. Thanks!

Make sure that you check the box next to "GPIB" on the second screen of the instrument wizard. Also, make sure that what you are seeing in Measurement and Automation Explorer (MAX) is the most recent case (refresh your screen). It is possible that the instrument is offline, but since MAX doesn't automatically refresh everytime a change is made, it may appear that the instrument is still being detected.
The following link may help.
http://zone.ni.com/devzone/conceptd.nsf/2d17d611efb58b22862567a9006ffe76/8e2f0a10f99519268625680400644435?OpenDocument
Kim L.
Applications Engineer
National Instruments

"How can i control the instrument with SCPI command by Borland C++ v3.1 using RS232 port"

"hi....
I've ever controlled some instrument by GPIB interface using Labview 6.0...it's really easy to implement .....but the problem is that i hvae to control those instrument under the pure DOS environment now ..so i have to abandon the using of GPIB interface and Labview ....then i choose the RS232 interface with programing the Borland C++ v3.1 and sending the SCPI command by bioscom()....but it got no response at all......so i am wonder if i can control those instrument by using RS232 interface and Borland C++ v3.1 to implement a pure Dos program????if yse,how can i do and is there any sample can be refer to ????
thank you for you help"

Hello Alvin-
We do not have any sample code for programming RS 232 in C on our website. However, you may want to looks at these links for general troubleshooting tips for serial:
Serial Communication Starting Point
How to Do a Serial Loopback Test
Regards,
Ray Kong
NI Applications Engineer

Is it possible to control a GPIB instrument by the instrument through GPIB

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