Keysight DAQ970A User Guide

Using an External Pull-Up
In general, an external pull-up is required only when you want to set the output “high” value greater than
TTL levels. For example, to use a +12V external power supply, the value of the external pull-up resistor is cal-
culated as follows:
V
cc
= 12 VDC
I
max
= I
out low
× safety factor = 1 mA × 0.5+0.5 mA
The value of the logic "high" level with the external 24 kΩ pull-up resistor is calculated as follows:
Driving External Switches
You can use two digital output channels to control an external switch. For example, you can drive the Key-
sight 876X series of microwave switches using an external power supply and two digital output channels.
The state of the 2-to-1 multiplexer is changed by setting the appropriate output bit low (0).
Keysight DAQ970A User's Guide 225
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Keysight DAQ970A Specifications

General

Scan Rate	Up to 450 channels/sec
Connectivity	USB, LAN, GPIB (optional)
Display	4.3-inch color LCD
Operating Temperature	0 °C to 50 °C
Number of slots	3 slots
Measurement Types	DCV, ACV, DCI, ACI, 2-wire resistance, 4-wire resistance, frequency, temperature, capacitance
Voltmeter	6.5 digit
Resolution	22 bits
Memory	Non-volatile memory