Watlow F4T User Manual

Watlow F4T • 141 • Chapter 5 Function Reference
Interpolated
The output is equal to the scaled input plus the offset. The scaling curve is composed of line-
segments connecting the ten points in numerical order as shown in the illustration below. The
output changes gradually as the input increases or decreases.
The points of the scaling curve must be in ascending or-
der of the input value such that Input Point 1 is the lowest
value to be scaled, Input Point 2 is the next higher value
and so on. If fewer than ten points are required, set the
unused input points equal to the last point. For example,
if the curve requires eight points, use points one to eight
for the curve and set points nine and ten equal to point
eight.
Signals
Direction
Label Type Function
Receiver
- - - - Analog Signal to be scaled
Transmitter - - - - Analog Scaled signal with offset applied
Function
To scale the input according to a curve made up of interpolated line segments defined by ten
points, set Function to Interpolate.
Units
Set the units of the output value.
Options:
• Source: the output has the same units as the signal connected to the top receiver.
• None: the output is a pure number without units.
• Absolute Temperature: the output is a temperature on the Celsius or Fahrenheit scale.
For example, 33° F as an absolute temperature is one degree above the freezing point
of water. An absolute temperature can be used as a set point or compared with other
temperatures to determine which is hotter or colder.
• Relative Temperature: the output is a relative number of degrees, not an absolute
temperature. For example, the difference between the two measured temperatures,
120° C and 100° C is 20 degrees, but it is not the temperature 20° C. A relative tem-
perature is appropriate for use as a calibration offset or a deviation alarm set point.
• Power: the output is a percentage with 100% representing full power and 0% represent-
ing no power.
• Process: the output is in units of measure other than degrees Fahrenheit, degrees Cel-
sius or relative humidity.
• Relative Humidity: the output is a measurement of percent relative humidity (%RH).
Input
Output Point 10
Output Point 1
Input Point 10Input Point 1
Output
Interpolated

Watlow F4T Specifications

General

Inputs	Thermocouple, RTD, mA, V
Outputs	Relay, SSR, mA, V
Communication	Ethernet, Modbus RTU
Data Logging	Yes
Certifications	CE, UL, cUL, RoHS
Control Modes	PID, On/Off
Power Supply	100 to 240 VAC
Operating Temperature	0 to 50°C
Enclosure Rating	IP65
Display	4.3 in. (109 mm) color touch panel LCD
Control Loops	Up to 4