Newtons4th PPA500 - RS232 Connections

PPA5xx/15xx communications manual
1-6
1.3 RS232 connections
The RS232 port on the instrument uses the same pinout as
a standard 9 pin serial port on a PC or laptop (9-pin male
‘D’ type).
Pin
Function
Direction
1
DCD
in (+ weak pull up)
2
RX data
in
3
TX data
out
4
DTR
out
5
GND
6
DSR
not used
7
RTS
out
8
CTS
in
9
RI
not used
The instrument will only transmit when CTS (pin 8) is
asserted, and can only receive if DCD (pin 1) is asserted.
The instrument constantly asserts (+12V) DTR (pin 4) so
this pin can be connected to any unwanted modem control
inputs to force operation without handshaking. The
instrument has a weak pull up on pin 1 as many null
modem cables leave it open circuit. In electrically noisy
environments, this pin should be driven or connected to
pin 4.
To connect the instrument to a PC, use a 9 pin female to 9
pin female null modem cable:
1 & 6
-
4
2
-
3
3
-
2
4
-
1 & 6
5
-
5
7
-
8
8
-
7