Crystal XP2 User Manual

PN: 2975 Rev F, 3/2004
Page 13 of 24
C R Y S T A L
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Reset
!RST This command schedules a reset. There will be a three second pause before
the XP2 resets; during this time, no commands or queries should be sent to
the unit. When the unit resets, a product identification string, called the Boot
Signature, is sent. (See the Programming Tips section for more information.)
Some communications noise, including a serial framing error, is possible on
reset. Resetting the XP2 clears the tare (zero) value, clears the peak high and
peak low values, enables automatic shutdown after 20 minutes of inactivity
(resetting that timer to 20 minutes on reset), and selects the first pressure unit
on the XP2 (which can vary with product type, but will be consistent for each
reset operation). After a reset, you should query and/or select appropriate
measurement units using the “?P,U” and “!I,P” commands. If the reset
command fails to operate properly, or appears to “lock up” the device, contact
technical support.
Disable/Enable Peak Display
Prevent peak pressure readings from being displayed.
!NPK Prevents peaks from being displayed.
!PKS Enables peak button operation (default).
Acknowledgment of a Command
The XP2 always returns some indication to let you know a command or query was received
and acted on. For queries, the return of the measurement data is the acknowledgment.
For commands, possible acknowledgments are “A”, “N” or “X”, followed by a comma then a
single digit. The digit indicates whether there were any reception errors. The combination is
left justified.
A The XP2 understood the command and acted on it.
N The XP2 did not understand the command, due to either syntax or reception
errors.
X The command was understood, but is not implemented at this time.
Following an “A”, “N” or “X”, the single digits mean the following:
Ø There were no reception errors.
2 Buffer overflow.
4 Framing error.
6 There were both buffer overflow and framing errors
Example acknowledgment:
A,Ø Understood the command and acted on it. No reception errors.
N,4 Could not understand the command because there was a framing error.
N,Ø Could not understand the command, even though it was received without errors,
so syntax must have been wrong.

Crystal XP2 Specifications

General

Accuracy	±0.25% FS
Display	LCD
Pressure media	Non-corrosive gases
Operating temperature	32°F to 122°F (0°C to 50°C)
Measurement Range	0 to 15 psi
Operating Humidity	90% RH (non-condensing)