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VISA Read error durning comunication with ALICAT MB Mass flow meter.

Re: VISA Read error durning comunication with ALICAT MB Mass flow meter.


Moseq wrote:

Yes , as I wrote before first of all I Have used original labview software. After using diagnostics tool I Have reached this subVI and post an issue. I dont know what commands I should use, there is nothing about it in manual. What tool allows me to snoop What is being sent by any software from and to Device ? I'm new to this stuff, That is Why I came Here Smiley Wink


What do you think the entire RS-232 / RS-485 Output and Input section is all about?  Those look suspiciously like commands to me.  Smiley Wink

I have to admit that they do appear to be quite complicated - which is probably why they supply drivers in the first place.  Furthermore, the settings aren't "random" - they all appear in the manual.

 

Instead of giving up on the manual, read it.  Then use that knowledge to set up the drivers - it's all there.  Then run the examples.  Then come back and shower us with accolades because you got it up and running with our help.  Smiley Wink

Bill
CLD
(Mid-Level minion.)
My support system ensures that I don't look totally incompetent.
Proud to say that I've progressed beyond knowing just enough to be dangerous. I now know enough to know that I have no clue about anything at all.
Humble author of the CLAD Nugget.
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Message 11 of 14
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Re: VISA Read error durning comunication with ALICAT MB Mass flow meter.


Moseq wrote:

. What tool allows me to snoop What is being sent by any software from and to Device ? I'm new to this stuff, That is Why I came Here Smiley Wink


Something like this

FREE Serial Port Monitor RS232 Communication Software Data

It's been awhile since I've used any of these, so I can't claim what is the best and what to avoid.

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Message 12 of 14
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Re: VISA Read error durning comunication with ALICAT MB Mass flow meter.

Hi there,

 

My name is Kevin Gudenkauf, and I am a test engineer at Alicat Scientific. I would be happy to help troubleshoot the issues you are experiencing and answer any questions that get brought up. 

 

First: the previous statements from the other members are all definitely valid. Alicat devices have RS-232 communication by default, unless ordered otherwise, and make use of this in a simple text command/response format. At the most basic level, the communication can be done in an old-school terminal style where a single command is sent by the user and a response is read back out (we actually have a free Serial Terminal application on our website that is pre-configured for speaking with our devices: http://www.alicat.com/support/software-drivers/). Our Flow Vision SC program and the LabVIEW drivers are actually making use of the same set of RS-232 commands, but simply take it one step further, parsing the data and bundling the commands into more user-friendly user interfaces.

 

The LabVIEW examples all include a sub-VI in the initialization phase ("COM Port Initialization.vi") that establishes a connection with a desired COM port and sets the necessary COM port settings (stop bits, parity, termination characters, etc.), and should be present in any LabVIEW code that is establishing a connection to an Alicat device (in place of a VISA Read). The user-definable settings should be set to match the settings of the Alicat (COM port should be set to the COM number that the Alicat is connected to, baud and unit ID should be set to match the values shown on the Alicat's front panel menu).

 

If the device is operating as intended through Flow Vision but not when running a LabVIEW driver example (assuming you have fully closed all other programs that try to access the specific COM port, such as Flow Vision), the most common issue I have seen is actually that the downloaded driver folder has not yet been unzipped and is being run from the compressed folder. This is far more common than you may think, and is thankfully the easiest to solve (unzipping the folder and trying to run an example program from there). 

 

If it is still not communicating properly with all other programs closed first and the files being located in an uncompressed folder, it is usually accompanied by other programs (such as Flow Vision or Serial Terminal) having issues as well and requires a little more troubleshooting to narrow down the cause (most often due to a missing ground reference or swapped 232 Rx/Tx wires). In these cases, Serial Terminal is actually the best fallback program for helping to determine where the issues lie as it can pinpoint things like garbled return text due to a floating ground reference.

 

Please let me know if this helps or if the issue is still present, and I will be more than happy to troubleshoot this further for you - either by forum posts or through email (kevin@alicat.com).

Kevin Gudenkauf
Test Engineer
kevin@alicat.com
7641 N. Business Park Drive
Tucson, AZ 85743 USA
Phone (520) 290-6060
www.alicat.com
Message 13 of 14
(161 Views)

Re: VISA Read error durning comunication with ALICAT MB Mass flow meter.


Kevin_Alicat wrote:

Hi there,

 

My name is Kevin Gudenkauf, and I am a test engineer at Alicat Scientific. I would be happy to help troubleshoot the issues you are experiencing and answer any questions that get brought up. 

 

First: the previous statements from the other members are all definitely valid. Alicat devices have RS-232 communication by default, unless ordered otherwise, and make use of this in a simple text command/response format. At the most basic level, the communication can be done in an old-school terminal style where a single command is sent by the user and a response is read back out (we actually have a free Serial Terminal application on our website that is pre-configured for speaking with our devices: http://www.alicat.com/support/software-drivers/). Our Flow Vision SC program and the LabVIEW drivers are actually making use of the same set of RS-232 commands, but simply take it one step further, parsing the data and bundling the commands into more user-friendly user interfaces.

 

The LabVIEW examples all include a sub-VI in the initialization phase ("COM Port Initialization.vi") that establishes a connection with a desired COM port and sets the necessary COM port settings (stop bits, parity, termination characters, etc.), and should be present in any LabVIEW code that is establishing a connection to an Alicat device (in place of a VISA Read). The user-definable settings should be set to match the settings of the Alicat (COM port should be set to the COM number that the Alicat is connected to, baud and unit ID should be set to match the values shown on the Alicat's front panel menu).

 

If the device is operating as intended through Flow Vision but not when running a LabVIEW driver example (assuming you have fully closed all other programs that try to access the specific COM port, such as Flow Vision), the most common issue I have seen is actually that the downloaded driver folder has not yet been unzipped and is being run from the compressed folder. This is far more common than you may think, and is thankfully the easiest to solve (unzipping the folder and trying to run an example program from there). 

 

If it is still not communicating properly with all other programs closed first and the files being located in an uncompressed folder, it is usually accompanied by other programs (such as Flow Vision or Serial Terminal) having issues as well and requires a little more troubleshooting to narrow down the cause (most often due to a missing ground reference or swapped 232 Rx/Tx wires). In these cases, Serial Terminal is actually the best fallback program for helping to determine where the issues lie as it can pinpoint things like garbled return text due to a floating ground reference.

 

Please let me know if this helps or if the issue is still present, and I will be more than happy to troubleshoot this further for you - either by forum posts or through email (kevin@alicat.com).


Great to see Alicat patrolling these boards!  Smiley Happy

Bill
CLD
(Mid-Level minion.)
My support system ensures that I don't look totally incompetent.
Proud to say that I've progressed beyond knowing just enough to be dangerous. I now know enough to know that I have no clue about anything at all.
Humble author of the CLAD Nugget.
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Message 14 of 14
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