Future Design MCTB 4.3, Руководство пользователя

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MCTB
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The
Alarm output function activates the Alarm 3 configuration settings for assigning the type of alarm logic to
apply to output 4. When the alarm condition is active, the output will turn on.
The
Reverse alarm output function activates the Alarm 3 configuration settings for assigning the type of alarm
logic to apply to output 4. The output will be normally “on” when this function is selected. When the alarm
condition is active, the output will turn off.
The
Event output function allows the output to be turned on and off via an automatic program or manually
through the MCTB
runtime application to act as a “soft” switch to turn system components on and off.
The
Retransmit process value and Retransmit setpoint value functions allow the loop control board output
to retransmit the current input value or control set point to remote devices such as a chart recorder.
The
DC power supply output function must be selected when the output type ordered for the loop control
board output 4 is a transmitter power supply.
The
Manual event output only function is similar to the Event output function above as it allows the output to
be turned on manually through the MCTB runtime application to a
ct as a “soft” switch to turn system components
on and off. However, the output cannot be controlled via an automatic program which allows the output to be
controlled separately regardless of program operation.
The
Math/Logic event output only function allows the output to be controlled only by a logic equation (See
section 4.6 Math/Logic Configuration ). The output will not be accessible through the runtime application as a
“soft” switch like the event/manual event only selections.
4.2.22 Output 4 Failure Transfer
The output 4 failure transfer setting is used to set whether the output should be on (1) or off (0) when there is
an input failure, i.e., sensor break. The setting applies to alarm output functions only.
4.2.23 Output 4 Low/High Limit Values
The output low and high limit values can be set when the output 4 function is set for retransmit process or
setpoint value. They are used to set the minimum and maximum percentage of the output range for the installed
output type.
For example, the standard range of the mA output is 0-20mA. In order to use the output as a 4-20mA output,
the low limit value would need to be set to 20% (20% of 20ma = 4ma). For the voltage output, the default range
is 0-10VDC. In order to achieve a 1-5VDC output, the low limit would have to be set to 10% (10% of 10VDC is
1VDC). The high limit would then have to be set to 50% in order cut the output span in half to get a maximum
output of 5VDC.