User`s manual

3-42 RGA Command Set
SRS QMS Gas Analyzer
• The detector’s zero and the internal scan parameters are checked and
corrected at the beginning of each scan resulting in a slight delay before the
scan actually starts.
• 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).
• 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:
• 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 ECU buffer is
flushed.
• 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.
• 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