DH Instruments PPC2+, Руководство пользователя

Страница: 121 / 166

PPC2+™ Operation and Maintenance Manual
Page 113
©2001 DH Instruments, Inc.
UNIT
Purpose Read or set the pressure display unit and measurement mode.
Command
Query
“UNIT unit (, ref”)”
“UNIT unitg (, ref”)”
“UNIT unita (, ref”)”
“UNIT?”
Classic “UNIT= unit (, ref”)”
“UNIT= unitg (, ref”)”
“UNIT=
unita (, ref”)”
“UNIT”
Arguments
unit:
ref:
The text corresponding to the pressure unit.
The optional unit reference temperature only if the unit is “InWa”.
Remarks This program message determines what unit and what measurement mode is used
to display pressure measurements. Refer to the UNIT section of the manual for a
detailed list of the units.
The unit text must be followed by ‘a’ if an absolute measurement mode is desired, or
else a gauge unit will be assumed. The unit text can optionally be followed by a ‘g’
to specify a gauge measurement mode also. There can be a space between the unit
text and the ‘a’ or the ‘g’.
If the unit specified is “InWa”, an optional second argument “
ref” can be set. The
“ref” can be 4, 20, or 60 corresponding to InWa at 4 °C, 20 °C or 60 °F. If this
second argument is not given when the unit is “InWa”, then the reference
temperature will be at 20 °C.
The fifth character of the reply will always be ‘a’ for an absolute unit, or ‘g’ for a
gauge unit. White spaces will proceed this character if needed. The temperature
reference will be added to the reply only if the unit is “InWa”.
Example
(enhanced)
Cmd sent:
Query reply:
Sent:
Query reply:
“UNIT kPaa”
“kPaa”
“UNIT InWag, 4”
“inWag, 4dC”
Example
(classic)
Sent:
Reply:
Sent:
Reply:
“UNIT=kPaa”
“kPaa”
“UNIT=InWag, 4”
“inWag, 4dC”
Errors ERR# 7:
ERR# 6:
ERR# 20:
The
unit is invalid.
The ref is invalid.
Absolute measurement mode and altitude units are not allowed with
a gauge RPT.
See Also Sections 3.2.2, 7.3, 3.4.1