Keithley 2700 User Manual

9-6 Limits and Digital I/O Model 2700 Multimeter/Switch System User’s Manual
Digital outputs
The digital I/O port has five digital outputs. Each digital output can be used as a sink to
control devices (e.g., relays), or as a source to provide input to external logic (TTL or
CMOS) circuitry. The simplified schematic for the digital outputs are shown in
Figure 9-3.
Note that this illustration shows the schematic for one digital output. All five digital output
circuits are identical.
Figure 9-3
Digital I/O port simplified schematic
The five digital output lines (pins 1 through 5) are controlled by limit operations. Each of
these five outputs correspond to the following limit operations:
Digital Output 1 - Low Limit 1 (LO1)
Digital Output 2 - High Limit 1 (HI1)
Digital Output 3 - Low Limit (LO2)
Digital Output 4 - High Limit 2 (HI2)
Digital Output 5 - Master Limit (logical OR of the four above limits)
+5V
4.75k
(Pull-up)
Pin 9 - Digital Ground
Digital Output
Pin 7 (+5V to +33V)
Digital Output
Flyback Diode
Control
Line
33V
Model 2700

Keithley 2700 Specifications

General

Type	Digital Multimeter
Measurement Functions	DC Voltage, AC Voltage, DC Current, AC Current, Resistance, Frequency, Temperature
DC Voltage Range	100 mV to 1000 V
AC Voltage Range	100 mV to 750 V
Frequency Range	3 Hz to 500 kHz
Temperature Range	-200°C to +1372°C
Display	Vacuum Fluorescent Display
Connectivity	IEEE-488, RS-232
Channels	10
Power Supply	100V to 240V AC, 45Hz to 66Hz
DC Current Range	10 µA to 3 A
AC Current Range	10 µA to 3 A
Temperature Measurement	Thermocouple, RTD