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6 high/low alarm, 7 transmitter – Measurement Computing CB-COM-7012 User Manual

Page 68

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CB-7012, CB-7014, CB-7017 User’s Manual

ignore the digital output command @AADO(Data).

3.6 High/Low Alarm

Some analog input modules, such as the CB-7012, are

equipped with the high/low alarm function. When the alarm func-

tion is enabled, the digital otput DO0 is the low alarm indicator,

DO1 is the high alarm indicator, and the digital output command

to change the DO0 and DO1 is ignored. The alarm function is to

compare the analog input value with given high alarm value and

low alarm value. There are two alarm types as follows:

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Momentary Alarm: the alarm status is cleared when the

analog input does not exceed the alarm value.

If Analog Input Value > High Alarm, DO1 (High alarm) is on,

else DO1 is off.

If Analog Input Value < Low Alarm, DO0 (Low alarm) is on,

else DO0 is off.

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Latch Alarm: the alarm is cleared only when the user sends a

command to clear.

If Analog Input Value > High Alarm, DO1 (High alarm) is on,

else if Analog Input Value < Low Alarm, DO0 (Low alarm) is

on.

3.7 Transmitter

A transmitter is an instrument that converts the signal

from a sensor to a 4 to 20 mA or to a 0 to 5V signal level.

Transmitters can provide driving power and have compensation

circuits for the sensor signal. The output may be linearized and

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