5 Function blocks
5.13 DC, PID controller
Control Relay easy800
11/11 MN04902001Z-EN
www.eaton.com
187
5.13 DC, PID controller
This function block is available for easy800-SWD from device version 01 and
for easy800 standard devices from device version 04.
32 PID controllers are provided.
Contacts and Coils
You use the coils of the function block to activate it, the individual elements
of the PID controller and manual mode.
DANGER
A knowledge of closed-loop control is required in order to use
the PID controllers.
The control system must be familiar to the user so that the PID
controller can function correctly.
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Three manipulated variables can be output independently of
each other:
•
One manipulated variable can be output via an analog
output.
•
Two other manipulated variables can be processed via two
pulse-width modulated outputs.
However, it is in most cases useful to run no more than three
closed-loop controllers per program simultaneously. If your
application requires more than three closed-loop controllers,
distribute them over several programs. You can structure your
projects by selecting the controller number.
Example: Project with 3 devices:
•
Program 1: Controller DC 10, 11
•
Program 2: Controller DC20, 21 and 22
•
Program 3: Controller DC30.
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If you are using the function block in time consuming
applications such as in conjunction with an FT signal smoothing
filter, you should not program any other time consuming
applications on this device, such as visualizations on the MFD.
The refreshing of screen(s) can increase the cycle time and thus
restrict the controller function. Distribute the applications
among two or more devices that you can interconnect via
easyNet.
Contacts
Meaning
DC..LI
Closes when exceeding the manipulated value range.