Section 2: General operation
Models 707B and 708B Switching Matrix Reference Manual
2-8
707B-901-01 Rev. B / January 2015
Figure 11: Models 707B and 708B digital I/O ports
Pin
Description
1
...
14
Digital I/O #1
...
Digital I/O #14
15-21
Ground
22
+5V D (fused, 600 mA)
23
Not connected; pin reserved for future use
24
Not connected; pin reserved for future use
25
+5V D (fused, 600 mA)
If you were using a Model 707A or 708A, see
Using Models 707A and 708A compatibility mode
page B-1).
Connecting cables
Use a cable equipped with a standard male DB-25 connector (Keithley Instruments part number
CA-126-1).
Digital I/O lines (pins 1 through 14)
The port provides 14 digital I/O lines. Each output is set high (+5 V) or low (0 V) and can read high or
low logic levels.
+5 V output
The digital I/O port provides a +5 VDC output that is used to drive external logic circuitry. Maximum
combined current output for all lines is 250 mA. These lines are protected by a self-resetting fuse with
an hour recovery time.
