DH Instruments PPCK PLUS, Operation And Maintenance Manual

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PPCK+™ Operation and Maintenance Manual
Page 69
©2001 DH Instruments, Inc .
4. R
EMOTE
O
PERATION
4.1 OVERVIEW
Most of the PPCK+ front panel functions can also be executed by commands from a
remote computer. The host computer can communicate to the PPCK+ using the PPCK+ COM1
RS232 port or the IEEE-488 port.
Before writing code which makes use of PPCK+ remote commands, familiarize yourself with its
operating principles by reading Sections 2 and 3 of this manual.
4.2 INTERFACING
Sending a program message to the PPCK+ will place it into remote mode. The remote indicator in
the lower left hand corner of the PPCK+ front panel lights when the PPCK+ is in remote mode. It also
flickers when a program message is received. The menus usually accessed from the front panel are
locked out while in remote. The [ESCAPE] key returns the PPCK+ to local operation unless the
“REMOTE” program message was sent to the unit, which locks out all keypad operation.
4.2.1 RS232 INTERFACE
4.2.1.1 COM1
The PPCK+ COM1 RS232 interface is located on the back of the unit. It is a 9-pin
female DB-9F connector configured as a DCE device. Data is transmitted out of the
unit using pin 2, and is received on pin 3. This allows a normal pin-to-pin DB-9M to
DB-9F RS232 cable to be used to connect to a DTE host.
Handshaking is not required or supported. The COM1 receive buffer is
80 bytes deep. If you overflow the buffer by sending too much data, the data will
be lost. Because of this, you
must send a single program message at a time and
you must wait for the PPCK+ to reply from the previous command before issuing
another command.