• An offset of 100 % is chosen to achieve 100 % output at the set point.
• Full range of output is selected. As this is output for a fan, it may be preferred to use a minimum output.
• Standard settings are used for M-Logic min./max. events.
• No relay settings are configured, as this is an analogue function.
Below is an example of M-Logic lines for this application. Logic 1 makes sure that the regulation is active and the output is
calculated as long as the engine is running. Logic 2 forces the fan to maximum speed during cool-down to ensure efficient cool-
down.
The fan then functions as in the description below.
When the engine is started and running, the regulation is activated and an output is calculated. When either the intercooler or jacket
water coolant exceeds their set point, the output starts to increase from 0 %. The input that results in calculation of greatest output is
prioritised at all times, making sure that both systems are supplied with adequate cooling. During stop sequence, the fan is forced to
max. output, ensuring most possible cooling. The output remains at 0 % until the engine is started again.
This is an example that uses inverse output combined with 0 % offset. The application is an engine with electric thermostat control.
During engine start-up, it is preferred to start the output before the set point is reached, to help avoid overshooting the set point too
much. This is obtained by using inverse output with no offset. The diagram below illustrates this function if the controller is
configured as straight proportional without integral or derivative action. With these settings, the output is 100 % when the set point is
reached, and the beginning of the output is determined by the proportional gain.
Temp. Output
90 °C 100 %
0 %
Time
DESIGNER'S HANDBOOK 4189341275A EN Page 196 of 196
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