Agilent Technologies U2802A manual Open Thermocouple Detection

Models: U2802A

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Features and Functions

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Open Thermocouple Detection

The U2802A provides a built- in 10 MΩ resistor on each TC+ terminal, which is pulled up to the internal +15 V power supply rail. This resistor can be enabled or disabled via the digital I/O pins on Rear Connector 2. When enabled, this 10 MΩ pull- up resistor and the 10 MΩ pull- down biasing resistor will cause the output from any unconnected thermocouple input channels to saturate to the maximum output voltage. The U2355A and U2356A devices can read this saturated channel and detect that a particular channel has an open thermocouple input.

Trigger, Counter, External Timebase, and Analog Output

The U2802A provides a direct access to the analog and digital trigger lines, counter channels, external timebase input, and analog output channels from the U2355A and U2356A devices. These lines are routed directly from the Rear Connector 1 and 2 to the J60 screw terminal connector. Please refer to pin description for Connector J60 on page 43. Precautions should be taken when driving high slew rate and frequency clocks into the Counter and External Timebase lines to avoid excessive noise coupling into other analog and digital lines. If excessive coupling or crosstalk is observed, clock output drive strengths and slew rates should be lowered to reduce coupling while still maintaining proper digital function.

Agilent U2802A 31-Channel Thermocouple Input User’s Guide

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Agilent Technologies U2802A manual Open Thermocouple Detection