Example code for tescoms er3000

[Florache]

Are you using the ER3000 to pilot a flow booster? In this case you need external feedback; you can not use the internal feedback.

Hope this help.

Regards,

Florache

[Peter_B]

Hi Florache,

it is being used to regulate the flow through a precision flow meter (a Molbloc made by DHI).  By regulating the pressure to a fixed value we regulate the flow.  Internal feedback is working OK.

We added another regulator just prior to the ER3000 to further stabilise the input pressure..

[Florache]

Ah, so you are using the flowmeter as a feedback, is that correct?

In my case I am preparing to design a system with 3 Tescoms and the requirement is to be able to switch from external to internal feedback and vice versa. The Tescom library that someone posted here does not include this feature. This would be a new command that I will have to include, I guess.

[Peter_B]

No, not using the flow meter for feedback.  The ER3000 set point is set using via adjusting an external analog voltage and feeding that into it. The ER3000 translates that voltage into a particular pressure and adjusts its output pressure to match that required pressure.  The ER3000 does this with a combination of opening its inlet port or outlet exhaust port.  The ER3000 is not setup in external feedback mode, it is setup for internal feedback mode - it internally adjusts its output pressure to match the analog setpoint fed to it.

regards

[jlguthri]

We are using RobCole's Tescom Driver.llb ‏driver for the Tescom ER3000.  Works great, but noticed something funny.  Every once in a great while, we get an error when using the Read Setpoint command.  Specifically, it looks like it is kicking up a CRC error due to some data being missing.   Strangely, it does the exact same thing again, if we repeat the command, or add some pause between the commands, etc.

Took the file Tescom ER Commands.vi and added some logging functions.  Ran the whole thing in a loop where it cycles between the commands:  Set Pressure, Read Setpoint, and Read Pressure randomly.  

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Any ideas why I'm loosing data so randomly, yet repeatablly?  etc   I feel like I'm missing somehing simple...

[jlguthri]

Never mind… figured it out…   LabVIEW’s default termination character is 0xA, and the default behavior is to stop reading when encountered..

Had to ignore the terminations

http://www.ni.com/white-paper/4256/en/