Commands and Tips for Third-Party Devices
Varian 3400 and 3600 GCs: Tips for Operation

Method

For the 3600 GC:  
The driver always uses Method 1. The method is automatically activated and overwritten with the settings in Chromeleon.

For the 3400 GC:  
The driver for the Varian 3400 GC cannot identify whether a reset was performed on the instrument or a different method was selected. Therefore, Dionex recommends that you always activate Method 1 before Chromeleon connects to the instrument and that you do not change this setting while Chromeleon controls the instrument.

Setting Properties

You can set properties only if the GC is not in Sample, Run, or RunEnd mode. If you set a property for the 3400 GC although the GC is in one of the above modes, execution is postponed until the GC is no longer in this mode. A message is written to the Audit Trail. If you set a property for the 3600 GC although the GC is in one of the above modes, a message is written to the Audit Trail but the command will not be executed.

The only commands and properties that can be used after an Inject command are: temperature gradients for the column oven, Acquisition On/Off, Delta, Average, and Step. Therefore, define all properties that are required for the method before the Inject command. A Reset command can always be sent.

If you want to include the temperature for an isocratic column oven in a program, define the temperature before and after the Inject command, and at the final program time. Otherwise, runtime calculation will not be correct.

Example:

Entering a Temperature Gradient

Temperature gradients can be defined only for the column heater.

Enter the temperature gradient either directly, by selecting the Flow command on the Control menu, or via a Program.

Chromeleon supports a temperature profile with up to four ascents. The maximum change in temperature is 50°C per minute. Descending temperature profiles are not supported. The GC returns to the initial temperature when the gradient is completed.

3600 GC: Flow / Pressure

The gas chromatograph maintains a constant pressure or flow for column A or column B, depending on the value that was entered last. This is how the column is selected.

Example:

If the following command was entered last:

 Injector_B.Flow = 1

the flow for column B is kept constant at 1 ml/min.

For an overview of the Varian 3400 GC, refer to Hardware Installation  Varian 3400 GC in the Administrator Help section.

For an overview of the Varian 3600 GC, refer to Hardware Installation  Varian 3600 GC in the Administrator Help section.