DH Instruments PPC2+, Manual

Page: 106 / 166

PPC2+™ Operation and Maintenance Manual
©2001 DH Instruments, Inc.
Page 98
PASSTHRU
Purpose To allow the host PC to communicate with a device connected to the PPC2+ 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Remarks This program message is a replacement for the ‘#’ program message which is
obsolete.
The PPC2+ COM2 port can be used to communicate to another RS-232 device
(such as another PPC2+). This allows the user to use one COM port or IEEE-488
port on the host computer to communicate with the PPC2+ 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 PPC2 COM2 receive buffer to see if a
message has been received on COM2 from the device. This message received by
the COM2 port must be terminated with a carriage return or a carriage return and a
line feed. Only one message will be retained by the COM2 port. The label “COM2:”
will precede the message text. If the COM2 receive buffer is empty, then the reply
will just be ‘COM2:”
Example
(enhanced)
Cmd sent:
Query reply:
Query reply:
“PASSTHRU VER”
“COM2:DH INSTRUMENTS, INC PPC2+ VER1.01a”
“COM2:” (If the COM2 buffer is empty)
Example
(classic)
Sent:
Reply:
Reply:
“PASSTHRU=VER”
“COM2:DH INSTRUMENTS, INC PPC2+ VER1.01a”
“COM2:” (If the COM2 buffer is empty)
See Also “COM2”, “#”