The Interface Solution Experts
15
CPT
PC-Programmable Signal
Isolater/Converter
Output if Measurement OFF
Choose “Zero Range” to read zero volts or mA at
output if measurement was off.
Choose “Stay Last” to read the last value held before
the measurement was off.
Note:
Once you have confi gured all parameters,
download to the unit by either selecting “Download
Confi guration” in the Confi guration dropdown menu
located in the Communications bar or by clicking the
button.
Output Damping
Output Damping allows you to introduce a delay into
the response of your unit in order to stop short-lived
spikes from setting off alarms. Output Damping is
activated when the value set in the “Output Step
Threshold” fi eld is exceeded.
1. To enable output damping, select the “Enabled”
button. If you do not wish to use the damping feature,
then select “Disabled”.
2. Insert a value between 1 and 16mA in the “Output
Step Threshold” fi eld. This is how much of an output
step change is allowed in a specifi ed time frame
before fl agging the software.
3. Insert a value between .5 and 120sec in the
“Damping Sec” fi eld. This is the amount of time it will
take for the output to reach 63% of the step output
change once the input exceeds the value in the
“Output Step Threshold” fi eld.
By checking the appropriate box in the Other Damping
Options section, you may also choose to select Output
Damping to occur upon power up or start up from
a PC, upon broken wire failure detection or upon
resolution of broken wire failure.
A typical damping situation would be described as a
step change in output which causes the output to go
from 5.6mA to 20mA. After fi ve seconds the output
reaches 14.58mA which equals 63% of the output
step change. This is graphed in Figure 8.
Figure 8. Typical Damping Scenario
In this case, an instrument malfunction or
Adc/EEPROM failure may be to blame.
A possible source for the occurence above is a
rapid change on the input. Another possiblity would
be an existing output level of 5.6mA upon Start
Measurements from a PC.
Figure 9 gives another damping example where the
output has been driven upscale to 23.6mA. After
fi ve seconds the 63% output change is reached at
16.98mA.
Figure 9. Damping When Output Driven Upscale to 23.6mA
