UNAP Data Setup DCM Help

The UNAP instrument has two Dual Current Monitor channels, which are identified as Channels 0 and 1. These channels have a very wide range and are very sensitive to current measurements.  Each channel is independent and comprises 12 gain stages numbered 0 through 11. Current is measured accurately with a dynamic range of 3 x 10-14 amperes to 3 x 10-4 amperes. The reported value for each channel is the average current during the measurement period. 

Any change MUST be sent to the UNAP instrument by clicking on the Save button.

DCM Setup

Gain Mode	The Gain Mode may be set to Fixed or Automatic. When the mode is set to Automatic, the appropriate gain stage will be selected automatically by the UNAP, depending on the current input. When the Gain Mode is set to Fixed, the gain stage is locked into a preset stage.
Fixed Gain	When the Gain Mode is set to Fixed, this parameter sets the gain stage that will be used.
Fine Gain Settings	To increase the accuracy of the DCM channels, each gain stage has an associated Fine Gain Setting. To change the fine gain setting for a particular gain stage, the desired gain stage for a DCM channel must be selected and then entered. After all of the fine gain settings for both channels have been set, changes to the UNAP must be saved using the Save button at the bottom of the page.
Offsets	Each of the 12 gain stages are coarse gain settings for the measurement circuitry. To improve the accuracy of the circuit, the base or offset of each gain stage is measured and subsequently used to compute a resulting measurement. The offsets are measured by opening the input circuit and measuring the apparent offset. The results of these values and the time at which they were last measured are displayed here. The displayed values are the results of the most recent Take Offsets action and cannot be changed manually.
Interval	The UNAP may be configured to take offsets automatically every week, every day, or never. The schedule for the UNAP to take offsets automatically is configurable with the parameters settable here. If the UNAP is in an active trigger at the time an automatic offset is scheduled, 30 minutes will be added to the schedule and the UNAP will try again at the new time. This time offset will occur until there are no active triggers.
Manual	The Take Offsets Now button provides the user the ability to trigger a manual measurement of the offsets. The process may take up to 30 minutes to complete. Clicking on the Take Offsets Now will initiate the action immediately and does not require the user to click on the Save button.

Bias Voltage Setup

Bias Voltage

The Bias Voltage is provided to support the DCM circuit. If the DCM circuit is not being used, then it should be turned off. When on, the voltage should be set to the desired setting and the Save button clicked to inform the UNAP instrument of the new setting.