Can Labview control remote GPIB instruments with Modems?

[rogchan]

My company has a new walkie talkie system called TETRA. Nokia THR850 is the TETRA handset model we are using. According to the user manual of the handset, it can be used as a modem. Please click the link below for some information of the handset.

http://www.nokia.com/nokia/0,4879,1482,00.html

If LabView could control my remote GPIB instruments with this handset, I would be able to acquire data from anywhere to my office, which would save me a lot of effort. Please let me know if this is possible? If yes, what is the simplest way? I am a mechanical engineer with limited electronics and programming knowledge, but I am a intermediate LabView programmer.

Please help.

[LesHammer]

> If LabView could control my remote GPIB instruments with this handset ...

That would depend upon whether or not the handset could control GPIB. Does it have a GPIB, USB or LAN port on it? (USB-GPIB and LAN-GPIB converters are available.) Can you download Windows apps (like VISA) to it? LabVIEW can do remote apps over LAN to another computer, but I do not know enough about your handset to answer the question.

Les Hammer

[Anonymous]

In article <5065000000080000009EA50000-1042324653000@exchange.ni.com>,
"rogchan" wrote:

> If LabView could control my remote GPIB instruments with this handset, I
> would be able to acquire data from anywhere to my office, which would
> save me a lot of effort. Please let me know if this is possible? If yes,
> what is the simplest way?

I'm not sure what kind of control you require but since you're working
with GPIB equipment it's safe to assume you don't require real-time
control.

The simplest way I know of is to send email messages. Most mobile phones
can send and receive email messages. Write a LV app that simply checks an
email account for new messages (this app is sitting on the machine that
has GPIB and/or DAQ equipment). When a new messa
ge is found, download it
and parse it for the proper commands: "start test", "stop test", or "get
test status". You may want to simulate the SCPI commands commonly used
with the GPIB equipment. When it finishes the test, it could sent you a
short, textual summary that can be read in the LCD of your mobile phone.

All you need is a POP client to check for messages from the phone and an
SMTP client for sending messages to your phone. Luckily, these tools have
already been developed for you. Use the OGIC library on OpenG.org:

http://openg.org/tiki/tiki-index.php?page=OpenG+Internet+Connectivity+Tools

Of course, this requires an alway ON connection like broadband dsl or
cable. If you only have a dialup connection, you could just have your PC
dial out to your ISP every hour or at certain times of the day. The LV
app could check for new commands or send its queue of data to the mobile
phone.

You can dial into you PC like you were asking about but this seems more
complicacted to me.
What if you change phones or don't have one that
allows dial-up to the PC? Doesn't seem like a good long-term solution.
Perhaps someone else can provide more advice in this area.

-Kevin

[rogchan]

Dear All,

Thanks for your advice. I prefer using the TETRA radio handset (Nokia THR850), as it is my company's own radio system, I can make use of it for business use free of charge.

The handset (Nokia THR850) can be connected to serial port of any PC with a special cable, and that is the only other data interface with other external devices. As the handset's user manual mentioned that it can be functioned as a 9600bps modem, I think my question can be modified to be "Can labview control my remote GPIB instruments with two modems - one connected to the LabView PC in my office, and the other connected to my GPIB instruments located in a remote area?"

You are right that my appication does not need real time data acquisition.

I have an idea about th
e hardware setup, but I don't know if this is feasible. My idea is that

Connecting a 9600bps modem with LabView PC using RS232. On my GPIB instrument side, the other modem is connected to the NI RS232-GPIB converter which is connected to my GPIB instrument at the same time. I wonder if I can send GPIB commands from the LabView PC to the remote GPIB instruments by dial-up connection between the two modems. I wish you can tell me that there is a way that can make the modems working transparently in the setup as if the LabView PC is control the GPIB instrument with a RS232 cable, RS232-GPIB converter only, because learning programming with AT commands is a very steep learning curve for me.

So, is this possible? If not, is there any other way.

I have already had simple, but working setup collecting thermocouple and mini-amp signals with multiple GPIB data multi-plexers (HP34970a) and a LabView PC directly connecting to the data multiplexers with GPIB cables.

Roger

[DiegoF]

Hi,

Here is the manual for the GPIB-232CT-A. It seems that you would need to operate the device as a GPIB controller (S Mode).

From your description it seems that the modems would give you a transparent way of extending the RS-232 communication. The PC would see a serial port and the GPIB-232CT-A would see another port. These device have no (and need no) knowledge of the wireless system in between. In this case, operating the GPIB-232CT-A would be the same as connecting it locally to the PC.

The manual mentions that you can use NI-488.2 to manage the GPIB-232CT-A as a plug in GPIB board. This is not sup
ported in the newer manuals, but the serial commands are described in the manaual. You can check the GPIB driver version page for more info on the supported drivers.

DiegoF
National Instruments.

[rogchan]

Dear Diego,

Thankyou very much! I am glad to know the setup I mentioned may work. I cannot test the conceptual setup until two special cables, which are the serial interfaces of the two Tetra Radio Handsets (the two modems), are delivered.

The OS of my LabView computers are either Windows 98 or Windows 2000. Could you tell me how to make the modems working transparently to extend the RS-232 communication of my LabView PCs? Can I do that simply by setting up a dial-up connection for the modem attached to my LabView PC in "Control Panel" and dial to the other modem attaching to the GPIB-232CT-A? Will Windows see the serial port of the remote modem?

Thanks for your help!

Regards,
Roger

[DiegoF]

Hi,

You'll have the modem documentation. I'm not familiar at all with it. In my response I assume that it is posible to use the wireless devices in this way. If that is not the case, then this particular hardware won't work. There are other wireless rs-232 extenders available.

DiegoF
National Instruments.