Stanford Research Systems RGA100, Operating Manual And Programming Reference

Page: 167 / 362

Tuning Commands 6-63
SRS Residual Gas Analyzer
Tuning Commands
CE?
Description : Calibration Enable Query.
Echo: JP100 setting.
Query the Calibration Enable/Disable jumper (JP100) status. An internal jumper
(JP100) on the digital (i.e. top) electronics board of the RGA’’s ECU box can be
configured by the end-user to enable/disable the modification of the peak tuning
parameters. The CE query command returns the JP100 setting in ASCII format with a
<LF><CR> terminator. The two options for the query response are:
0. JP100 jumper is in the Calibration Disabled position. Peak Tuning Parameters
protected by the JP100 jumper.
1. JP100 jumper is in the Calibration Enabled position. Peak Tuning Parameters not
protected by the JP100 jumper.
Parameters: Only one possible command format is allowed
CE?
Error Checking:
The only acceptable parameter is a question mark. The absence of a parameter (i. e. EC)
is treated as a bad-parameter error.
DIparam, param: 0 - 255, *, ?
Description : DI Parameter adjust (Peak Width Tuning command).
JP100 Jumper protected.
Echo: Query Response.
Program the value of DI during the Peak Width Tuning Procedure. The parameter (one of
four peak tuning parameters) represents the DI value, in bit units.
Warning: Please read the Peak Tuning Section of the RGA Tuning Chapter before using
this command.
The RGA Head adjusts the DC levels of the quadrupole filter during measurements so
that constant mass resolution is automatically available throughout the entire mass range
of the spectrometer. The bulk of the DC voltage is supplied by a DC power supply whose
output is linearly related to the RF amplitude. The rest of the DC voltage (DC_Tweek) is
provided by the output of an 8 bit digital-to-analog converter (DAC). The firmware uses
two Peak Tuning Parameters : DI (Intercept) and DS (Slope), stored in the non-volatile
memory of the RGA, to calculate the 8 bit settings of the DAC according to the linear
equation:
DAC8 (m) = DS
.
m + DI