DH Instruments PPC2 AF - Page 78

PPC2 AF OPERATION AND MAINTENANCE MANUAL
© 1998 DH Instruments, Inc. Page 72
UL(=)
Purpose: Read or set an upper limit for the current transducer and range.
Syntax: “UL”
“UL=n”
Arguments:
n: The upper limit pressure in the current pressure units.
This value is always in absolute units if the transducer is absolute, or gauge
units if the transducer is gauge.
Remarks: The PPC2 AF has an upper limit for each range of each transducer. New targets can not be
greater that this value. If the pressure does exceed the upper limit, the pressure display will
flash, and the unit will stop generating. Manual increases in pressure will not be allowed as long
as the pressure is above the upper limit. Decreases in pressure will be allowed. This feature
should always be used to prevent accidental over pressure of a device under test.
Example: Command: “UL=1000”
Reply: “1000.00 kPa a”
See Also: 3.2.4
VAC(=)
Purpose: Read or set the vacuum status.
Syntax: “VAC”
“VAC=n”
“VAC=0”
Arguments:
n: ’0’ if the PPC2 AF exhaust port is open to atmosphere.
’1’ if the PPC2 AF exhaust port is connected to a vacuum pump.
Remarks: The PPC2 AF must be informed if a vacuum pump is being used.
Example: Command: “VAC=1”
Reply: “VAC=1”
See Also: 3.3.1
VENT(=)
Purpose: Read, execute or abort a vent process.
Syntax: “VAC”
“VAC=n”
Arguments:
n: ’1’ to start a vent process.
’0’ to abort a vent process and close the exhaust valve.
Remarks: The PPC2 AF vents by generating close to atmosphere, and then opening the exhaust valve.
This command will return a ‘0’ if the exhaust valve is closed, or a ‘1’ if the exhaust valve is open.
Because of this, a reply to a “VENT=1” will always be a “VENT=0” unless the unit is already
vented.
Example: Command: “VENT=1”
Reply: “VENT=0”
See Also: 3.1.2.2