Chromatography Forum

Well, I finally had success using the 35900E to provide the TTL outputs, but I had to do it in a sort of indirect way because of the Dionex detector.

The detector should turn the suppressor off when receiving a TTL signal at the appropriate input. For some reason, this detector would not do that. Nor would our other Dionex detector. I could use the TTL signal to change the detector range or trigger a recorder mark, but the suppressor turn off feature would not work. It seems rather arbitrary that this feature alone would not work on multiple detectors.

So I set up two methods on the detector: one to run the analyses with the suppressor at the appropriate setting, the second method with the suppressor off. The detectors will increment method numbers using a TTL signal, so I finally got it to work this way.

Thanks for everyone's help and input.

You can set the pins on the Digital I/O connector on the 35900E from Agilent ChemStation by using macro commands. For the Channel A Digital I/O connector, use the command:
A$ = SendModule$("ADC","ATWR xxxxxxxx")
where the 'x' equals:
0 to set the corresponding pin LOW
1 to set the corresponding pin HIGH
T to toggle (invert) the corresponding pin
X to leave the corresponding pin unchanged.

The pins relative to the command are 98765432. So, to set pin 2 low and ignore the rest, send: A$ = SendModule$("ADC","XXXXXXX0")

For Channel B Digital I/O use BTWR.

Oh, and by the way, to read the current pins use:

A$ = SendModule$("ADC", "ATWR ?")

Then print A$, if all pins are high, it will read 11111111

Great, thanks!