ICP DAS USA I-7521, User Manual

Page: 126 / 148

I-7521/I-7522/I-7522A/I-7523/I-7524/I-7527 User’s Manual,Ver2.5 Aug.2015
126

TxD: send commands to the RS-232 HOST

RxD: receive commands from the RS-232 HOST

DTR: Set the HP34401A as active HIGH to enable the RS-232
HOST to send commands

DSR: Set the RS-232 HOST as active HIGH to enable the HP34401A
to send the results back to the RS-232 HOST
The demo program, hp34401a.c, is designed to allow a Host PC to be
connected to an HP34401A. Refer to the companion CD for the source
code of the hp34401a.c file. The flow chart illustrating the functionality
of the hp34401a.c file is shown below:
Set the multimeter
to remote-control
mode
Any key
pressed?
start
N
Y
Ask for
measuring
Acquire
reading
Set the multimeter
back to local mode
end
Note: the PC COM port should be 16550 compatible.