Stanford Research Systems RGA100, Operating Manual And Programming Reference

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6-44 Scan and Measurement Commands
SRS Residual Gas Analyzer
Scan and Measurement Commands
AP?
Description : Analog Scan Points Query.
Echo: Query Response.
Query the total number of ion currents that will be measured and transmitted
during an analog scan under the current scan conditions.
Important: The query response does not include the extra current (4 bytes)
corresponding to the total pressure measurement performed at the end of all
analog scans (Please see SC command for details).
The number of points (i.e. ion currents) retuned over RS232 is calculated based
on the MI, MF and SA parameter values. Number of points = (MF - MI) * SA +
1. The first point corresponds to the mass MI and the other (MF-MI)*SA are
from scanning to MF with SA measurements (steps) per amu. Each point
transmitted represents an ion current and as such corresponds to 4 bytes being
received by the host computer.
The AP query is used to verify that the RGA and the host computer agree on the
number of bytes that will be exchanged over RS232 during the analog scan.
The total number of bytes sent out to the host computer during an analog scan is
obtained multiplying by four the number returned by the AP query.
Parameters: This command is a query, and can only have one parameter format:
AP?
Error checking:
The only acceptable parameter is a question mark.
The absence of a parameter (i. e. AP) is treated as an error.
HP?
Description : Histogram Scan Points Query.
Echo: Query Response
Query the number of ion currents that will be measured and transmitted during a
histogram scan under the current scan conditions.
Important: The query response does not include the extra current (4 bytes)
corresponding to the total pressure measurement performed at the end of all
histogram scans. (Please see HS command for details).