DH Instruments PPCH-G, Руководство по эксплуатации и обслуживанию

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4. REMOTE OPERATION
Page 105 © 2007 DH Instruments, a Fluke Company
PRR
Purpose Read the next available pressure, rate and on-board barometer reading.
Query “PRR?”
Classic “PRR”
Remarks
The next available Ready condition, Q-RPT or utility sensor pressure, rate of pressure change,
and barometric pressure is replied in the current pressure unit of measure. Each data field is
separated by a comma, and is returned in the following order:
ready, pressure UNITS, rate UNITS/s, atm UNITS
Here are the field descriptions:
ready: ‘R’ if the current pressure Ready criteria has been met,
‘NR’ if the criteria has not been met (see the “SR” program message).
pressure: The measured pressure for the active Q-RPT or utility sensor in the current
pressure unit. This is followed by the current pressure unit.
rate: The measured rate of pressure change for the active Q-RPT or utility sensor
in the current pressure unit per second. This is followed by the current
pressure unit of measure.
atm: The pressure measured by the PPCH-G on-board barometer in the current
pressure unit (and always absolute). It is displayed in it’s full resolution. This
is followed by the current pressure unit.
After receiving this program message query, the PPCH-G replies back with
the data once a new pressure measurement cycle is complete. This can
take up to 1.5 seconds.
Example
(enhanced) Query sent:
Reply: “PRR?”
“R,23.0626 MPa a,0.011 MPa/s, 0.097001 MPa a”
Example
(classic) Query sent:
Reply: “PRR”
“R,23.0626 MPa a,0.011 MPa/s, 0.097001 MPa a”
See Also “PR”, “QPRR”, “SR”, “ATM”
3.1.1, 3.5.7.2
PS
Purpose Set a new target pressure and start a new pressure control cycle. Allows the test volume to
be specified which causes the pressure control cycle to be executed omitting the automated
control configuration routine.
Command “PS n (,v) ”
Classic “PS= n (,v) ”
Arguments n:
v:
The target pressure in the current pressure units.
The volume of the system connected to the PPCH-G TEST port in cm
3
(cc).
This argument is optional and should be used only to reduce pressure-
setting time in known volumes.
Remarks The PPCH-G sets the specified target pressure using the current control settings and mode.
Control continues until a new target pressure is set (except in monotonic mode), the PPCH-G
goes into LOCAL mode, or an “ABORT” program message is executed. If the given target is
‘0’, the PPCH-G vents.
The “PR?”, “PRR?”, “STAT?”, or “SR?” program message queries can be used to monitor the
progress of the pressure setting routine.
If the optional “ v ” argument is used, the PPCH-G does not attempt to perform its test volume
determination routine at the beginning of the pressure setting procedure, but instead uses the
volume specified for the pressure control. This can reduce pressure set times when operating
into a consistent volume. The “v” argument should only be used in automated conditions,
where the test volume is constant and the configuration does not change. This argument is
only an approximation value, and it may be adjusted empirically for correct operation. A
higher “v” setting speeds up the generation with a higher risk of significant control overshoot.
A lower “v” setting slows down the generation and reduces overshoot.
Example
(enhanced) Cmd sent:
Reply: “PS 1000”
“1000 kPa a
“ (no reply if IEEE-488)
Example
(enhanced) Cmd sent:
Reply: “PS? 1000”
“1000 kPa a
“
Example
(classic) Sent:
Reply: “PS=1000, 75” (includes test volume definintion)
“1000 kPa a
“
Errors ERR# 6
ERR# 8
ERR# 12
ERR #18
The target pressure is out of range.
Active external RPM4 timeout.
Pressure has exceeded maximum limits.
This command not valid in “rate” generation mode.
See Also “PR”, “PRR”, “STAT”, “SR”, “QPRR”, “RS”
3.2.2, 3.3.10, 3.2.1