Watlow F4T User Manual

Watlow F4T • 102 • Chapter 5 Function Reference
Heat Proportional Band Inner Loop [1 to 5]
Set the proportional relationship between heat power (%) and the process value (typically
temperature). This setting determines how big a correction the proportional part of the PID
control algorithm makes when the process value deviates from set point. A smaller propor-
tional band yields a larger power adjustment for a given deviation from set point.
This parameter applies only when Heat Algorithm is set to PID. This parameter is set automat-
ically by autotuning the loop.
Range: 1 to 99,999 ºF or units
1 to 55,555 ºC
Cool Proportional Band Inner [1 to 5]
Set the proportional relationship between cool power (%) and the process value (typically tem-
perature). This setting determines how big a correction the proportional part of the PID con-
trol algorithm makes when the process value deviates from set point. A smaller proportional
band yields a larger power adjustment for a given deviation from set point.
This parameter applies only when Cool Algorithm is set to PID. This parameter is set automati-
cally by autotuning the loop.
Range: 3 to 99,999 ºF or units
1 to 55,555 ºC
Integral Inner Loop [1 to 5]
Set how aggressively the integral part of the PID algorithm acts. Integral acts to drive the pro-
cess value to set point by steadily adjusting the output whenever the process value deviates
from the set point. A smaller Integral setting yields a larger power adjustment for a given de-
viation from set point over a given time.
This parameter applies when either Heat Algorithm or Cool Algorithm or both are set to PID.
This parameter is set automatically by autotuning the loop.
Range: 0 to 99,999 seconds per repeat
Derivative Inner Loop [1 to 5]
Set how aggressively the derivative part of the PID algorithm acts. Derivative acts to prevent
the process value from changing too quickly. It can help minimize the effect of transient pro-
cess disturbances, but too much derivative can make the process slow to adjust to changes. A
greater Derivative setting yields a greater power adjustment for a given change.
This parameter applies when either Heat Algorithm or Cool Algorithm or both are set to PID.
This parameter is set automatically by autotuning the loop.
Range: 0 to 99,999 seconds
Heat Proportional Band Outer Loop [1 to 5]
Set the proportional relationship between heat power (%) and the process value (typically
temperature). This setting determines how big a correction the proportional part of the PID
control algorithm makes when the process value deviates from set point. A smaller propor-
tional band yields a larger power adjustment for a given deviation from set point.
This parameter applies only when Heat Algorithm is set to PID. This parameter is set automat-
ically by autotuning the loop.
Range: 1 to 99,999 ºF or units
1 to 55,555 ºC

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