Watlow F4T
®
• 10 • Chapter 1 Overview
Keep in mind that a FB can be a purely internal function (i.e., control loop, alarm, logic, etc...),
while they can also serve as a connection point between real-world devices
(i.e. thermocouple, heater etc...) and internal functions like a Universal Input connected to the
Control Loop PV input. To have an effect outside of the controller, an output FB must be
configured to respond to some other function. Functions and all associated dependencies
would be configured using Composer software. To learn more about setting up function blocks
see Chapter 2 of this ocument in the section titled "Configuring the Application with the Func-
tion Block Diagram View".
Outputs
Outputs respond to information provided by a function such as, heat power from the output of
the control loop, driving a digital output based on a profile event, turn a light on or off,
unlocking a furnace door or turning on a buzzer.
More than one output can be assigned to respond to any given function, i.e., more than one
output device could be connected to the heat output of the control block. Another example (not
shown), could use the (internal) output of the alarm function and connect it to any available
real-world output to trigger a flashing light and another real-world output that might be
connected to a siren.
What is a Profile
A profile is a set of instructions consisting of a sequence of steps. When a profile runs, the
controller automatically executes its steps in sequence. The step type determines what action
the controller performs. Steps can change temperatures and other process values gradually
over time, maintain the temperatures and process values for specific periods, or repeat a
sequence of steps numerous times. At each step the profile can activate or deactivate outputs
that control other equipment. Also a step can have the controller wait for specific conditions
before proceeding such as, waiting for a switch closure and/or a specific process value to be
detected by a sensor.
Data Logging
Controllers equipped with this feature will have the letter [J, K, L or M] in the fifth character of
its part number (see: F4T
®
Ordering Information). Logging can be enabled at any time and is
intended to capture real-time data for a user selectable list of data points. With firmware
revision 3.0 and above, several new features are available.
1. User can determine if logged files will be moved automatically and or manually.
2. Destination of the saved file can be directed to internal memory, USB thumb drive, TFTP
server or a Samba shared drive.
3. Based on user choice, files can now be encrypted (filename.enc) for security purposes and
or saved as comma separated values (filename.csv). Creating both file types allows
viewing of the csv file while maintaining the integrity of the encrypted file.
To learn more about configuring these options see the section in this user's guide entitled
Setting Up Data Log Files Using Composer.