Chromatography Forum

A 6890 Plus GC in a teaching lab is used twice a year for only a few samples every 6 months.
This year when we started up the instrument we got the introductory screen as if the Chemstation software (v5.04) had been newly updated (What's new and Tutorial popup). We were immediately suspicious since it hadn't been touched since the spring.

Problems that immediately showed up included not being able to edit or save any GC methods. This even though the the Chemstation access level had not been set to Operator (and no Manager access login screen showed up when Chemstation started up.

This problem was ultimately solved with a tip here in the Chromatography Forum (thanks): we edited the win.ini file to delete the "LEVEL=" line (we DID find an entry in that file "LEVEL=SOMETHING" etc). No clue how that came about since the instrument worked perfectly in the spring. (No angry chemistry students at our university...)

OK so now we are back to being able to edit and save our methods again.

But all is not OK in the Instrument | Edit| Detectors dialog for the 6890 FID:

We can light the FID by hand on the GC.
The FID's signal is being seen/recorded by Chemstation.
We can change the FID's heater temp setting (and click box) and its actual temp changes are reported in Chemstation and on the GC.
We can change FID Lit Offset value and that change is reflected in the software and on the GC.
We can turn the flame off and on in the software via flame and click box + Apply. Flame's actual toggles "on" to "off" in Chemstation as expected.

However, ALL the other software FID detector ACTUALS and SETPOINTS are greyed-out and therefore can't be edited (even though their click boxes work and those changes are reflected on the GC front panel.)

That is, the H2, air, and makeup setpoints can NOT be set in the software and when the flame is lit and H2, air and make gases are clearly flowing, the actuals are greyed-out and aren't reported in the software. Therefore we have no control on the H2, makeup, and air flows. Unlike our 7890A, the GC's FID flows CAN'T be set on the GC's front panel so we're in a fix.

No hardware, detector, cabling, or gas line changes have been modified on this instrument in many many years.
It seems that the chance that hardware problems initiated this problem is small.
We still don't know how the Manager access password got set but that does seems to be the genesis of the problems.

Reinstallation of Chemstation 5.02 and then upgrade to 5.04 (with a floppy disk!) did not affect/solve the problem. The "Level=" win.ini code line did not reappear after reinstallation so apparently the default setting is Manager, unpassworded,as we had experienced with this software for years.

Just to make this harder, the Chemstation logbook shows no errors on startup.

Otherwise the Chemstation software runs flawlessly, and of course we boot the GC before we boot Chemstation to avoid the "68GC is missing/not configured" error message.

Suggestions as to how we can gain control of our FID gas flows again would be greatly appreciated.

Thanks for your time in advance.

Red Head

Hello

Try to load default method (Default.M) and create simple method from scratch.
If it won't help you can try to disconnect FID from mainboard and remove it from configuration (so in Chemstation you will not see FID). Then connect it again and re-configure it.

Regards

Tomasz Kubowicz

... Unlike our 7890A, the GC's FID flows CAN'T be set on the GC's front panel ...

Why ? Shouldn't it be possible to control FID flows from the GC keyboard ?

"Normally" one can access setpoints through the front keyboard. Try turning computer off, and then 6890 GC on, and trying the front buttons.

"Normally" one can access setpoints through the front keyboard. Try turning computer off, and then 6890 GC on, and trying the front buttons.

And if you still can't control FID flows from GC then don't bother with ChemStation. The fault lies in GC.

Thanks for the responses.

Powering the GC back up and down doesn't solve the problem.

Since this GC doesn't have EPC there is no control of gas flows on the GC front panel.

kubowicz.tomasz I'm deep into your suggestion now. Here's where I am.

I can indeed disconnect the FID board (and a second detector cable) and make the GC sees no installed detectors.

When I boot Chemstation it can be reconfigured to not see the FID. So far so good, but the method's Detector icon still shows greyed-out gas flow choices in the Front detector software panel which it note has no detector. So there must be a pneumatics flow input too (although greyed-out).

So finally I found and unplugged the pneumatics board cable on the GC and rebooted. FINALLY, I see no Front detector or Back detector in the method at all. Great.

This is what kubowicz.tomasz suggested and, finally, it was accomplished.

The next step was reconnecting all detector components on the GC, confirming that the GC recognizes the FID front detector and front LCD panel H2, air, and makeup gas entries and rebooting Chemstation.

Alas the detector can be reconfigured into a new method, will see the FID, but the same grey-ed out gases setpoints occurs again.

All past (and hopefully future) suggestions appreciated.

Red Head

...
Since this GC doesn't have EPC there is on control of gas flows on the GC front panel.
...

Now I see. Since your GC has no EPC then you can't control respective gas flows from ChemStation and that's why gas control elements in ChemStation are greyed-out (IMHO ) .

Conclusion:

dblux_ ,
I was truculently writing my response to your last post, planning to express my annoyance that "of course I could control the GC's FID gas flows even though the GC didn't have EPC", when I stopped and thought about the analog gas gages on the left side of the instrument that I (then) remembered using to set the flow rates on the FID in a completely analog manner. I even remembered finding HP's famous (high temp, red rubber) FID chimney fitting to connect my bubble meter.

Well, if I used those gages to set the FID flows why would there be a Chemstation method to do this? Well, of course there isn't: software commands from Chemstation to the GC could only actually control gas flow rates if EPC were present, just as dblux_ states. Thank you, dblux_, for resetting me, and solving my problem.

Summary: the HP/Agilent 6890 gas chromatograph, without electronic pneumatics control, EPC, cannot control any gas flow rate via Chemstation software EVEN THOUGH the software (well, Chemstation version 5.04 anyway) does show uneditable fields for FID gas flow rates and actuals. And this software DOES have working on/off fields (toggling click boxes) for H2, air, and makeup gas, as well as the ability to light the FID's flame and shut it off, even though these same functions can be carried out on the GC front panel (if it's not software locked out).

http://www.chem.agilent.com/Library/use ... -90210.pdf

The Chromatography Forum's posts did help me solve the Manager password problem (see above, thanks) but, otherwise, as Emily Latella would say, never mind.

Thanks to all.

Red Head

... Thank you, dblux_, for resetting me, and solving my problem...

My pleasure.