DH Instruments PPC4, Руководство по эксплуатации и обслуживанию

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PPC4™ OPERATION AND MAINTENANCE MANUAL
© 2009 DH Instruments, a Fluke Company Page 156
NVENT
Purpose Read or set the status of TEST (-) (negative) vent valve (Gxxx or BGxxx Q-RPT only)
Command
Query
“NVENT n ”
“NVENT?”
Classic “NVENT= n ”
“NVENT”
Default “NVENT AUTO”
Arguments n: ’0’ to close the low vent valve.
’1’ to open the low vent valve.
‘AUTO’ for the PPC4 to automatically open and close the low vent valve.
Remarks A PPC4 with at least one Gxxx or BGxxx Q-RPT has a valve that is used to vent the TEST (-) port.
This valve is normally controlled automatically depending on current PPC4 operation but it can be
commanded to open or close using the “NVENT” command. The PPC4 may not immediately open
the negative vent valve when commanded to do so, as it checks to make sure that such an action
will not cause harm to the low pressure Q-RPT.
The reply includes two fields. The first indicates the low vent status. The second indicates whether
the low vent function is AUTO or MANUAL
Example
(enhanced)
Cmd sent:
Query reply:
“NVENT 0”
“0, MANUAL”
Example
(enhanced)
Cmd sent:
Query reply:
“NVENT? AUTO”
“1, AUTO”
Example
(classic)
Sent:
Query reply:
“NVENT=1”
“0, MANUAL”
See Also “VENT”
3.2.27.6
PASSTHRU
Purpose To allow the host PC to communicate with a device connected to the PPC4 COM2 port.
Command
Query
“PASSTHRU n
“PASSTHRU?”
Classic “PASSTHRU= n ”
“PASSTHRU”
Arguments n : The string to send out of the COM2 port. It must be less than 40 characters long.
Remarks Generally, the PPC4 COM2 port is used for communication with DHI RPM4s used as PPC4
external measurement devices.
The COM2 port can alternatively be used to communicate to another RS232 device (such as
another PPC4). This allows the user to use one COM port or IEEE-488 port on the host computer
to communicate with the PPC4 and another device. The Command format specifies and sends the
argument. A carriage return and a line feed (<CR><LF>) are added to the string that is sent.
The Query format is used to check the PPC4 COM2 receive buffer to see if a message has been
received on COM2 from the device. The message received by the COM2 port must be terminated
with a carriage return or a carriage return and a line feed. Only one message is retained by the
COM2 port. The label “COM2:” precedes the message text. If the COM2 receive buffer is empty,
then the reply is just be ‘COM2:”
Example
(enhanced)
Cmd sent:
Query reply:
Query reply:
“PASSTHRU VER”
“COM2:DH INSTRUMENTS, INC PPC4 VER1.01a”
“COM2:” (If the COM2 buffer is empty)
Example
(classic)
Sent:
Reply:
Reply:
“PASSTHRU=VER”
“COM2:DH INSTRUMENTS, INC PPC4 VER1.01a”
“COM2:” (If the COM2 buffer is empty)
See Also “#” , “COM2”
6.3.1.1, 6.3.1.2