EMKO ESM-9910 - 7. Control Algorithm; 7.1 ON;OFF Control

7.1.1 ON/OFF Control in ESM-XX10 Temperature Controller
7.1 ON/OFF Control
ON/OFF control form in temperature control output which has heating function
ON
OFF
Temperature
Temperature
Control Output
Temperature
Set Value
Hysteresis
Time
Time
ON/OFF control form in temperature control output which has cooling function
7. Control Algorithm
HYS
ON
OFF
Temperature
Set
Temperature
Control
Output
HYS
ON
OFF
Temperature
Set
Temperature
Control
Output
Temperature
Temperature
In ON/OFF control algorithm, temperature value is tried to keep equal to set value by
opening or closing the last control element. ON/OFF controlled system, temperature value
oscillates continuously. Temperature value’s oscillation period or amplitude around set value
changes according to controlled system. For reducing oscillation period of temperature value,
a threshold zone is formed below or around set value and this zone is named hysteresis. Action
of control output is described with figures below.
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