Keithley 2700 User Manual

9-10 Limits and Digital I/O Model 2700 Multimeter/Switch System User’s Manual
Source mode — logic control
The digital outputs can be used as logic inputs to active TTL, low-power TTL, or CMOS
inputs. For this mode of operation, the output lines can source up to 200µA.
CAUTION Each output line can source up to 200µA. Exceeding 200µA may cause
damage to Model 2700 that is not covered by the warranty.
Figure 9-5 shows how to connect a logic device to one of the output lines. When the
output line is pulled high, the transistor will turn off (transistor switch open) to provide a
reliable logic high output (>3.75V). When the output line goes low, the transistor turns on
(transistor switch closed) to route current to digital ground. As a result, a low logic output
(0V) is provided at the output.
If the second input (B) of the NAND gate is connected to another output line of the port,
the output of the NAND gate will go to logic 0 when both digital outputs are set high.
Figure 9-5
NAND gate control
Setting digital output
The OUTPUT menu (shown in Table 9-1) is used to control and configure digital outputs.
Menu items for the digital output include:
• DOUTPUT — Use to enable (ON) or disable (OFF) the digital outputs.
• PULSE — Use to enable (YES) or disable (NO) the pulse option for the digital
outputs.
Model 2700
4.75k
Pull Up Resistor
Pin 9
Digital
Output
Logic Device
NAND
B
A
Control
Line
+5V

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