Using Labview to talk to Datascan modules

[dsc78]

Hello,

I'm just getting started using LV7.1, and need a little help. I want to use LV to create a control sequence for 4 channels of a Datascan digital output module. The seqence will need to include a 30 sec interval between opening and closing the soleniod valves connected to each channel. At the moment we are using Orchestrator for data logging but may look at reading and writing multiple analog channels through LV.
My first question is where do I start? I have a sequence for each of the valves to open and close, and I will be using a serial connection to communicate. I haven't been able to find any VI for Datascan on the site, should I be using the instrument I/O assistant instead?

any help would be great.

[Stuart_R]

Hi there,

Let me just clarify; This device has a serial port available on it for direct connection?

Does it have a command set which you can use to send messages over the serial link?

What is the exact product that you are trying to interface to (link to web page available)? Have you searched Google for any VI's?

The 30 second interval could be implemented using the Wait(ms) function inside a sequence structure. First sequence opens the solenoid, second adds delay of 30 secs, third sequence closes solenoid.

Let me know more information on the specifics and I will gladly help you with the code.

[dsc78]

Hi,

The device uses an RS232 interface, but can also use RS485. Currently we are only using the serial connection due to the short distance between the measurement modules and the PC. Information on the Datascan modules can be found at the following address:

http://www.measurementsystems.co.uk/displaysubcat.asp?id=101&cid=1

The modules we are using are the type 7320 (16 channel analog input), and 7035 (16 channel digital output), which are linked via a bus cable.
The modules i assume have a command set, they are currently operating with the software supplied (Orchestrator).

I have searched through google but have not been able to find any VI's as of yet. I am however waiting for a reply back from Datascan on this issue. My real problem is that I am a complete novice when it comes to programming so you may find me asking stupid questions.

I thought i might start with something simple, like getting LV to talk to the device, and then reading an analog input (thermocouple). At the moment I don't know how, without a datascan VI i can really achive this. I'm assuming there will be several VI's for different routines (initiate, read, write, close, etc)

I hope this is enough information to start with, i will let you know if I get a response from Datascan on any Vi's available.

Thanks for your help

[Stuart_R]

OK, I see what you are trying to do here now. You really will need to get more information from them on what serial commands are available for you to use. Otherwise there is no way of knowing exactly what to send over the RS-232 link.

Once you know this, the application shouldn't be too complex. Let me know when you have more info on this and we can progress further. I've attached an LV example written in version 7.1. It doesn't actually do anything at present but should give you an idea of one way to structure the code.

[dsc78]

Hello,

I have just recieved the manual and VI's from Datascan, which should allow me to continue with this task. Thanks for your help I'll have a little play around and see what i can come up with. I have attached the files from Dscan in case i need to ask your advice.

Thanks again.

[dsc78]

For some reason the manual file was not with the VI's.

[Stuart_R]

Looks like you're all sorted then!

I've had a quick look at the vi's and shouldn't be much problem using these to structure your code. I did notice that at least some of the vi's have password protection and you won't be able to alter their functionality, but you may not need to anyway.

Good luck with the application, and let us know if you need further help.

[Ludwig72]

I cant use this driver with LabVIEW 9.0 - masscompile gets an error message: "LabVIEW Version 5.1 vi´s cant´t translated because they are too old"!?

What can I do now? How can I use this vi´s?

[K C]

Hi Ludwig,

The llb in the zip are converted to LV7 (see log file) You load this with LV 8. I hope you can also load this with LV9.

I don't have 9 yet. I think I am somewhere at the end of the update line. 

[Ludwig72]

Hi KC,

thank you for converting the file. Last week I found an LV8.2 licence and loaded it with this version. It seems that compatibility has changed in LV9.

Because the code is buggy (error while closing the VISA session) and password protected, I wrote my own driver now.

Ludwig.