Chromeleon 6.8 - How to record pressure?

[Joerg J]

Hi everybody

I have Chromeleon 6.8 running as acquisition software for two old-fashioned Kontron pumps, a Kontron UV detector and a radioactivity detector. Data acquisition for the two detectors is by a two channel A/D box (UCI-50). In the status window the system pressure is displayed, so I know the software knows the actual pressure, only I cannot select a channel to record it along my data. The help system tells something about a "virtual channel", but this is not detailed enough for me. Could someone please help me with a step-by-step guide?
Thank you in advance,

Joerg

[Alex J]

Hi Joerg,

I have some experience using a UCI-50 with CM6.8. Will need some detailed information on your set up. Can you supply the following-

1. Kontron pump type, eg Kontron 420.
2. Kontron detector types.
3. Physical cabling configuration for every module, eg UV detector analog out to Ch 1 on UCI-50.
4. When you state "Status Window", are you referring to a CM6.8 control panel. If so, which panel are you using.
5. Anything else you think is relevant.

Alex

[Joerg J]

Hi Alex,

I'll give you all information I have:

- The pump type is 420
- UV detector is 430A connected to Ch1 on UCI-50
- The radioactivity detector is Berthold LB 507 A connected to Ch2 on UCI-50
- Nothing else is connected to UCI-50 (only USB to the computer)
- The pumps are connected by a 7-point RS232 connector (pump side) to an RS232-to-USB box on the computer
- With "status window" I am referrin to the Chromeleon control panel:

The actual pressure is displayed by the blue bar beside the flow rate. Mouseover says "Pump.Pressure = 133 Bar"
- The connector on the pump back labeled "pressure" is not used

I hope that is sufficient.

Joerg

[unmgvar]

Joerg J

in newer pumps the driver is generally created to allow for pressure collection like a chromatogram, if this is your case then in the PGM you can choose to collect also the pump pressure

My guess is that it is not there, then you need to tell CM to allow you to take the pressure info the system anyway collects and transform it into a pressure information channel.
So here is the great part of CM, you can do it by creating a virtual channel of this information that is anyway monitored.

I suggest that you look at the help section of CM for this, in the index, under virtual channel of course. it explains how to set this up.
go to Virtual Channel Driver
then there choose: Virtual Channel Driver (VCD)
it is done in the chromeleon server section not in CM itself
then Configuring the Channels of the Virtual Channel Driver
then Program Examples for Virtual Channels (this is in CM itself after the channel is set in the CM server)

[Joerg J]

Alex,

thank you for pointing me into the right direction. For further reference I give a short stp-by-step guide:

1.) Open Chromeleon Server Configuration
2.) Right click on the Timebase needed, and select "Add device..."
3.) From the menu, select "Generic -> Virtual Channel Driver"
4.) Give the virtual driver an appropriate name. There is no need to change the default settings for the driver.
5.) Close Server Configuration and save.
6.) Open Chromeleon
7.) To activate the pressure channel, add the following lines to the .pgm file:

Code: Select all

VirtualChannel_01.Formula  Formula = Pump.Pressure
VirtualChannel_01.Type = Analog

in the header, and

Code: Select all

VirtualChannel_01.AquOn

and

Code: Select all

VirtualChannel_01.AquOff

at the appropriate time points.

Voilà!

[Alex J]

Well done Joerg, but it's unmgvar you need to thank. His advice pointed you in the right direction.
Alex