Stanford Research Systems RGA100, Operating Manual And Programming Reference

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6-46 Scan and Measurement Commands
SRS Residual Gas Analyzer
x
A Total Pressure measurement is performed at the end of each scan and
transmitted out to the host computer (Please see HP and TP
Commands).
x
The measurements are performed with the detector that is active at the time
the scan is triggered.
Parameters:
HS : Continuous scanning mode. The RGA produces a continuous string of
histogram scans.
A new command must be sent to the RGA in order to stop the scanning activity.
Once the command is received, the scan is immediately stopped, all transmission
is halted and the transmit buffer is flushed (
all remaining data is lost ). The new
command which stopped the scan is executed after the buffer is flushed
HS0 : Do nothing command. Commonly used to interrupt continuous scanning
mode.
HSparam, param:1-255: Multiple scans.The number of scans specified by the
parameter is executed. Scanning is immediately stopped when a new command is
received as in the case of continuous scanning.
HS* : The default parameter value is used for multiple scan excecution.
Default parameter value: 1 (single scan)
Error checking :
Number parameters must be within the specified range, and be integers.
No query format is allowed
Programming Tips:
x
Any command received by the RGA while scanning will immediately stop
the scanning process and clear the RGA’’s transmit buffer. Remember to also
clear the computer’’s receive buffer to reset the communications. The new
command which stopped the scan is executed after the RGA Head buffer is
flushed.
x
It is good practice to perform an analog scan before triggering a large set of
histograms to assure the correct tuning (i.e. correct peak locations and
widths) of the quadrupole mass spectrometer. Perform a complete Peak
Tuning Procedure as described in the RGA Tuning chapter of this manual if
shifts in the peak locations are observed.
x
The RGA has the ability to store a complete scan in its output buffer. The
scan remains in memory until all the data is transmitted out to the host
computer over RS232. As a result of the high acquisition rate of the RGA
there might be a delay between the time at which the data is collected and the
time at which a complete spectrum is displayed by the host computer. The