Figure 4.3 calculator link – Falcon F3400 User Manual
Page 37
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4
Configuration Menu
Select Input Type: Select based on the type of device connected to the input channel. Options
include:
Not Configured – Select when there is nothing connected to the input.
Analog 4-20mA – Select when the device connected to the input provides a 4-20mA output.
Digital NO – Select when the device connected to the input is a dry contact that is normally
open and closes on an alarm condition.
Digital NC – Select when the device connected to the input is a dry contact that is normally
closed and open on an alarm condition.
Digital Status – Select when the device connected to the input is a dry contact that only
needs to be monitored (status only), without alarms.
Thermistor – Select when the device connected to the input provides resistance output.
Gain and Offset: Applies only to Analog 4-20mA input types. Inputs like temperature,
humidity, pressure, etc. sensors connected to the F3400/F1000 convert information to a 4-
20mA signal. The F3400/F1000 reads this raw 4-20mA signal and calculates a value based on
the input and the predetermined gain and offset settings. The idea is to determine the correct
gain and offset values so that the F3400/F1000 calculates and displays an accurate reading - one
that corresponds closely to the sensor's reading (e.g., if the sensor measures a temperature of
50°F, the F3400/F1000 should display 50°F; if the sensor measures a temperature of 95°F, the
F3400/F1000 should display 95°F). If the gain and offset settings are incorrect, the F3400/
F1000 will calculate an incorrect value. Since the F3400/F1000's reading will not match the
sensor's reading, over the entire sensor range, missed alarms or nuisance alarms could result.
To set gain and offset values, click the Calculator link.
Figure 4.3 Calculator Link
Enter the sensor’s range and press the Calculate button. Click the Return to Input Configuration
link and the gain and offset fields will be automatically entered with the correct offset and gain
settings. Gain and offset values can also be determined by using the following formulas:
Gain for 4-20mA Transducer = (Sensor High Range Value- Sensor Low Range Value) / 4
Offset for 4-20mA Transducer = Sensor Low Range Value - Gain