Agilent LC/GC System Control (ICF)
Setting the Run Time

When creating methods for Agilent LC/GC systems that are supported by the Instrument Control Framework (ICF), users have to define a run time both in the Chromeleon PGM and the Agilent method.

In Chromeleon, the run time is defined by the data acquisition time, while in the Agilent method it is determined by the Stoptime and the (optional) Posttime. This topic describes how to set these parameters.

In the Chromeleon PGM Wizard

Data Acquisition Time

The acquisition time determines when data recording of the selected channels is enabled and disabled (AcqOn, AcqOff).

To specify the acquisition time:

• On the Acquisition Options page of the Chromeleon Program Wizard, type the start time and end time of data acquisition in the From and To box. It is recommended to start AcqOn at 0.00 min.

• Select one or more of the available auxiliary channels. The AcqOn and AcqOff times apply to these auxiliary channels and to the 'chromatogram' channels defined in the Agilent method.

After completion of the PGM wizard, the AcqOn and AcqOff times are written to the Chromeleon PGM script. Usually, the script's End time corresponds to the AcqOff time.

In the Agilent Instrument Method Editor

In an LC/GC system, the overall run time is derived from the maximum stoptime + posttime defined in the Agilent instrument method editor. The editor can be accessed from the Chromeleon Program Wizard: On the Agilent LC/GC System Options page, click Launch Agilent ICF IME to open the editor.

Stoptime

The stoptime determines the length of the run. It must be defined separately for each module and may be set to a specific value or to unlimited. After elapse of the specified time, the operating parameters of the instrument are reset to the values that were valid before the start of the run.

To specify the stoptime:

• In the instrument method editor, go to the tab page for each module.

• Specify the stoptime options for each module:

• Click As Pump or As Injector to use the same stoptime as the pump or the injector.

  –OR–

  Specify the appropriate time in the min box of the respective module to set an individual stoptime.  

Note:

Always make sure that a stop time is defined for at least the pump module of the system. If no stop time is defined at all, the Agilent method will run infinitely (whereas the Chromeleon PGM will end at the time defined with "End").

Posttime

Additionally, a post-run time, for example, for post-run equilibration, can be defined. You may set an individual time for each module or set posttime to Off.

Time Relations

The diagram below shows the time relations that exist between the above described parameters. The colored bars represent the method stages that are passed by each LC/GC module during analysis. The grey bars indicate the start of data delivery by the LC/GC modules versus start of data recording by Chromeleon.

Note that there is a time offset between start of data delivery and start of data recording. The offset results from the LC/GC system which starts to provide data a few data points prior to 0.00 min. As Chromeleon is not able to store data prior to 0.00 min, data provided before 0.00 will not be considered by Chromeleon.

In the example below, the sample run ends after 5 minutes, determined by Oven.Stoptime+Oven.Posttime.

Method settings are as follows:

Note:

For more information about run time deviation also refer to the Agilent online help for the respective detector driver.

Further Information

Agilent LC System Commands (ICF)

Agilent GC System Commands (ICF)

Creating, Modifying, Resolving and Printing Methods

Monitoring the Instrument Status

Miscellaneous Hints

Troubleshooting