Tektronix Keithley 2651A Reference Manual page 118

Model 2651A High Power System SourceMeter® Instrument Reference Manual
The following table provides pinout identification for the 9-pin (DB-9) or 25-pin (DB-25) serial port
connector on the computer.
Computer serial port pinout
Signal*
DCD, data carrier detect
RXD, receive data
TXD, transmit data
DTR, data terminal ready
GND, signal ground
DSR, data set ready
RTS, request to send
CTS, clear to send
RI, ring indicator
* The Model 2651A does not use all RS-232 signals. See
2-92).
2651A-901-01 Rev. C October 2021
Section 2: General operation
DB-9 pin number
1
2
3
4
5
6
7
8
9
Flow control and signal handshaking
DB-25 pin number
8
3
2
20
7
6
4
5
22
(on page
2-93