Technical Manual
Glass Room Temperature Controller Smart SCN-RTRGx.02
MDT technologies GmbH •
51766 Engelskirchen • Papiermühle 1
•
Germany
Phone: +49-2263-
880 • [email protected] • www.mdt.de
61
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In PWM control, the controller switches the control value according to the value calculated in PI
control, considering the cycle time. The control value is thus converted into pulse width modulation
(PWM).
PWM cycle
The PWM cycle is used for PWM control to calculate the switch-on and switch-off pulse of the
control value. This calculation is based on the calculated control value. A PWM cycle comprises the
total time from the switch-on point to the new switch-on point.
Example:
If a control value of 75% is calculated with a set cycle time of 10 minutes, the control value is
switched on for 7.5 minutes and switched off for 2.5 minutes.
In principle, the slower the overall system, the longer the cycle time can be set.
For PI control switching (PWM), the status can also be output as a percentage value.
The following communication objects are available for this:
Number Name/Function
Length Usage
12
Control value Heating
–
Send status
1 Byte Sends the status as a percentage value
12
Control value Heating/Cooling
–
Send status
1 Byte Sends the status as a percentage value
13
Control value Cooling
–
Send status
1 Byte Sends the status as a percentage value
Table 64: Communication objects
–
Status control value
