How do i communicate with AALBORG mass flow controller usinng labview?

[KB0710]

Hi Everyone,

I have been trying to read data from my AALBORG mass flow controller via VISA. I have taken the RS485 output and used an RS485 to usb converter made by silicon labs .since I'm new to labVIEW i want know if there is any mistake in the block diagram that i have made. I have been able to read the data from an indicator made from PIC18F2520 through the same converter from this VI.

Along with the Screenshots of the block diagram and front panel i have also attached the screenshots of the write commands to be sent (from the master) to the mass flow controller from the manual. 

Thanks in advance for helping. 

[GerdW]

Hi KB,

there are several problems in your VI:

• Don't open the port in each iteration inside the loop - especially when you close it only once after the loop!
• NEVER USE BytesAtPort when there is a TermChar in use!

Simplified:

[KB0710]

Hi Gred,

Thanks for the help. 

I tried reading from the MFC via the vi you suggested. i'm still not able to read anything. I'm wondering what is the reason. 

Thanks,

KB

[GerdW]

Hi KB,

---

@KB0710 wrote:

i'm still not able to read anything. I'm wondering what is the reason. 

---

When you "wonder what is the reason" you should check the error wire!

Which error do you get?

Do your serial port settings match with the device settings?

Is the serial port itself working correctly?

Can you check with some other software?

[KB0710]

Hi Gred,

I have checked the error. The error source is "VISA Read " with a code "-1073807339".

Apart from that every thing is fine. The port settings match the device settings. Also, i have tested it in a software provided by AALBORG instruments and it works fine. 

Is there anything that is should change in the VI?

Thanks & Regards

KB

[GerdW]

Hi KB,

do you append the correct TermChar when sending the command to your device?

(To my shame I forgot to show the display style-indication at the string constant, I set it to \-display mode to add the CR char at the end of the command message…)

[KB0710]

Hi Gred,

I changed the display style of the string control to '\' Display like you said and was able to get the response from slave.That was the one thing i had missed out.

Really appreciate you for guiding me through this.

Thanks

KB 

[KB0710]

Hi Everyone,

I have been trying to communicate with AALBORG Instrument's DPC mass flow controller. I am able to read the data from the flow controller via visa(the controller has a 485 output and i'm using an rs485 to usb converter to communicate). Now i want to be able to control the set point(digitally) using the same rs485 via VISA. I tried to find example online but it didn't help me much.

Since, I'm new to labVIEW (i'm using LabVIEW 14) I would really appreciate if someone helped me out with regards to this by guiding me to the right document or help me find the resources. 

Thank you in advance

KB 

[GerdW]

Hi KB,

please keep (related) things in one place instead of starting new threads for basically the same question!

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@KB0710 wrote:

Now i want to be able to control the set point(digitally) using the same rs485 via VISA. … guiding me to the right document or help me find the resources.

---

Why don't you read the "commands" which YOU provided in your own first message?

It mentions the command to change the setpoint…

[Devanshhv]

Hi, could you share the new vi screenshot?