Fieldpoint serial port communication?

[851624047]

Hi,

  I am a researcher from School of Biotechnology, Dublin City University, Ireland. I have been using Labview programming (version 8.2) for bioprocess monitor and control. I am using Fieldpoint (FP2010) module for data acquistion and control.  I've connected analog outputs from various controllers to appropriate channels and found data acquistion working fine using respective VI's. We have few instrument outputs which are need to be connected through serial interface on filedpoint's serial port. We are using  a multiplexer (B & B electronics) for channeling all serial outputs (of instruments) to serial port of Filedpoint. VI's developed for all serial interface of multiplexer ports  found working (data logging ok!) , when it is connected directly to COM1 port of PC. But when multiplexer serial interface is connected to serial port of Fieldpoint, the data values fails to log on the PC. Ethernet cable is used for interfacing filedpoint with PC. It seems the PC recognises COM1 port for serial interface but not serial port of Field point.

We have a driver software for multiplexer, where we already configured all serial input and output ports as required. How to configure PC to serial port present in Filedpoint instead of it using COM1?

I tried playing with MAX configuration as wells device manager of PC, but system couldn't recognise serial port of filed point.

kindly provide me a solution.

Thanks

Regards,

Senthil

[Wayne.C]

Senthil,

Because cFP can't run NI-VISA Server, the COM ports can't be directly accessed via ethernet from a remote host program.  To do the remote access, you need to embed a vi that can talk to the port.  Essentially you are creating your own server.  You can use the Shared Network Variables to get data in and out of this vi. 

[851624047]

Dear Centerbolt,

  Thanks for your reply. We are setting up data acqusition thru FP2000 in our new facility at our campus. The VI's developed for serial port interface were worked already (run by my previous colleagues) and data acquistion was made via ethernet cable. Is there any simpler option to fix it rather than embedding a new VI?

Regards,

Senthil

[Wayne.C]

Senthil,

If you want to use the COM port on the FP, then you will have to have some sort of vi embedded that handles the serial communication.  No way around that.  The vi that you have been using to talk via the PC's COM port will run the same on the FP.  FP supports VISA functions.  You just need to add some code to handle interface to host pc.

Other option would be to purchase an ethernet serial port and connect your instrument to that. 

[DirkW]

Hi,

There is a software component that normaly would provide the feature you are looking for. It is the VISA Server. Unfortunately this component is not installable by default on cFP 20x0 controllers because of memory limitations.

Your controller has enough memory, so you could try  to install the Server by hacking the driver installation configuration file for the NI-VISA server. Keep in mind that this is not an official feature and the usability could be limited.

Go to your   \\Program Files\National Instruments\RT Images\NI-VISA Server\4.x    folder and open the "install_81xx.cdf" file with your wordpad.

Add the bold line to the file as shown below:

<?xml version="1.0"?>
<?CDF VERSION="1.1"?>
<SOFTPKG NAME="{E62A7BA2-8ED9-4C4A-AFA1-0DE33A188D61}" VERSION="4.4" TYPE="VISIBLE">
    <TITLE>NI-VISA Server</TITLE>
    <ABSTRACT>Remote VISA Server -- Shares VISA resources over the network.</ABSTRACT>
    <IMPLEMENTATION>
        <DEVICECLASS VALUE="PXI"/>
        <DEVICECLASS VALUE="Desktop"/>
        <PROCESSOR VALUE="7002"/>
        <PROCESSOR VALUE="7063"/>
        <PROCESSOR VALUE="7151"/>
        <PROCESSOR VALUE="7175"/>
        <PROCESSOR VALUE="E002"/>
        <PROCESSOR VALUE="E001"/>

Save and close the file and close and reopen MAX. Go to your remote target and open the software installation tool. Now you should have the VISA server as an option for installation.

After installing it and reboot, go back to your remote target in max and go to Software/NI-VISA 4.x and choose VISA Options at the right page. Go to Aliaes and choose "ADD Alias".

Now enter ASRL1::INSTR into "Ressource Name" and "COM4" as Alias name for example. Now go to VISA Server /Security and add a * to allow access for every Host connected to your target.

Save your settings and change to MySystem/Software/NI-VISA 4.x and go to VISA Options at the right page. Go to Aliaes and choose "ADD Alias".Now enter visa://your remote IP address/ASRL1::INSTR into "Ressource Name" and "COM4" as Alias name for example. Save your settings.

Now you should be able to access your remote COM4 interface from your HOST, by using the COM4 alias within the VISA ressource control.

DirkW

[851624047]

Hi DirkW,

   Thanks for your response. I looked for NI-VISA SERVER folder on RT images and it was not found in it. Then I copied NI-Visa Server folder from other PC and added code to .cdf file as you mentioned. I tried to install NI-visa server via add-remove software option, but it is unable to install and I got  dialog box with following information.

NI-VISA 4.4 requires Microsoft visual studio 7.1 runtime support 1.0

NI-VISA 4.4 requires Labview RT 7.1.1

NI-VISA server 4.4 requires Microsoft visual studio 7.1 runtime support 1.0

NI-RPC 4.0.0.3.1 requires Microsoft visual studio 7.1 runtime support 1.0

NI-RPC 4.0.0.3.1 requires Labview RT 7.1.1

The current already installed software versions on MAX are

Labview RT 7.1

NI-IRDA RT 1.0.1

NI-Serial RT 2.5.3

NI-VISA 3.1

NI-Watchdog 2.1.0

Is it problem in software version incompatability? How can I resolve this?

Thanks

Senthil

[DirkW]

Wow, I didn't expect you to run this old version. Copying folders doesn't do the magic.

Two options here. 1. Get the newest version of LabVIEW from somewhere/someone. 2. Update your Software  in order: 1. LabVIEW 7.1.1  2. LabVIEW 7.1.1 Patch  3. LabVIEW RT 7.1.1  4. NI-VISA 4.4.1. The VISA driver should bring all mentioned support components to install the server.

DirkW

[TommyHelter]

Being familiar with your situation (I have done several projects with the FP-2120), I would have to point you in a similar direction as user "centerbolt" (as above).  The three best options are, 1) run the serial data acquisition direct from the PC comm port and application on the PC (use RS 485 short haul modems, if the length is needed), 2) get an Ethernet to Serial Converter (NI has several to choose from) or 3) write a simple VI to embed on the FP-2120 to aquire data and 'store and forward' via the Ethernet connection.

If you are going to continue to use NI and LabView in your environment and with this type of hardware, then the exercise in coding/configuring in option # 3 will be of significant value to you moving forward.

[8bitbanger]

After going down this road I suggest obtaining a ethernet->serial bridge. That along with a small Ethernet switch will be *so* much easier than trying to embed a serial 'tunnel'. I spent well over a month developing such an app and it is not as future-proof as the above method.

Check out LanTronix for the LAN->Serial bridge; they can be had for around $100USD.

[851624047]

Dear All,

  Thanks for your valuable responses. I decided to go for a serial - ethernet converter. Please anyone could suggest me the model no. of the same available in National instruments. Is it possible to use Serial - USB convesion cable for this purpose?

Best Regards,

Senthil