Rs-232 Connections - Keithley 6487 Reference Manual

9-18 Remote Operation

RS-232 connections

The RS-232 serial port can be connected to the serial port of a controller (i.e., personal
computer) using a straight through RS-232 cable terminated with DB-9 connectors. Do
not use a null modem cable. The serial port uses the transmit (TXD), receive (RXD), and
signal ground (GND) lines of the RS-232 standard. It does not use the hardware handshak-
ing lines CTS and RTS.
face and
panel is shown in
If your computer uses a DB-25 connector for the RS-232 interface, you will need a cable
or adapter with a DB-25 connector on one end and a DB-9 connector on the other, wired
straight through (not null modem).
(DB-9) or 25-pin (DB-25) serial port connector on the computer (PC).
Figure 9-4
Table 9-2 shows the pinout for the connector. The connector location on the rear
Figure 9-3.
Figure 9-4
RS-232 interface connector
5 4 3 2 1
Rear Panel Connector
Table 9-2
RS-232 connector pinout
Pin number
1 DCD, data carrier detect
2 TXD, transmit data
3 RXD, receive data
4 DTR, data terminal ready
5 GND, signal ground
6 DSR, data set ready
7 RTS, request to send
8 CTS, clear to send
9 No connections
RTS and CTS are tied together.
DCD, DTR, and DSR are tied together.
TXD and RXD are swapped on Model 6487 and PC so
that null modem cable is not required.
shows the rear panel connector for the RS-232 inter-
9 8 7 6
RS232
Table 9-3 provides pinout identification for the 9-pin
Description
Model 6487 Reference Manual