DH Instruments PPCH-G, Руководство по эксплуатации и обслуживанию

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PPCH-G™ OPERATION AND MAINTENANCE MANUAL
© 2007 DH Instruments, a Fluke Company Page 114
TPCVOL
Purpose Read or set the current estimate of test volume.
Command
Query “TPCVOL n ”
“TPCVOL?”
Classic “TPCVOL= n ”
“TPCVOL”
Arguments n: The volume of the system connected to the PPCH-G TEST port in cm
3
(cc)
Must be 0 – 1 000 cc
Default “TPCVOL 10”
Remarks This current volume that the PPCH-G believes is connected to its TEST port can be read back
or overridden using this command. The volume should be set only in automated conditions,
where the test volume is constant and the configuration does not change. This volume is only
an approximate value that may be adjusted empirically for correct operation. A higher setting
speeds up pressure generation with a higher risk of significant control overshoot. A lower
setting slows down pressure generation and reduces overshoot
Example
(enhanced) Cmd sent:
Reply: “TPCVOL 50”
“50”
(No reply if GPIB-488)
Example
(enhanced) Cmd sent:
Reply: “TPCVOL? 50”
“50”
Example
(classic) Sent:
Reply: “TPCVOL=50”
“50”
Errors ERR# 6 The volume was invalid.
See Also 5.5
UCOEF
Purpose To convert 1 Pascal to the current pressure units.
Query “UCOEF?”
Classic “UCOEF”
Remarks
The PPCH-G handles all pressure values internally in Pascal. The coefficient replied is
equivalent of 1 Pa in the current pressure unit of measure. This program message allows the
user to convert pressures. The reply will be in scientific notation if very small or very large.
Example
(enhanced) Query sent:
Reply: “UCOEF?”
“0.001000”
Example
(classic) Sent:
Reply: “UCOEF”
“0.001000”
See Also 3.3.2, 3.5.6, 7.2.1
UDU
Purpose Read or set the user defined pressure unit.
Command
Query “UDU label, ucoef ”
“UDU?”
Classic “UDU= label, ucoef ”
“UDU”
label: User unit label (4 alphanumeric char maximum). It cannot be an already
supported unit label.
ucoef : “User unit conversion coefficient (units/Pa).
Default “UDU USER,1.0”
Remarks The user defined unit must be set up with the program message prior to remote or local
selection.
Example
(enhanced) Cmd Sent:
Reply: “UDU MYUN, .001”
“MYUN, 0.001000”
(No reply if GPIB-488)
Example
(enhanced) Cmd Sent:
Reply: “UDU? MYUN, .001”
“MYUN, 0.001000”
Example
(enhanced) Sent:
Reply: “UDU=MYUN, .001”
“MYUN, 0.001000”
See Also 3.5.6, 3.3.2