gefran GTF-Xtra Installation And Operation Manual page 24

3.10 D (Pwm)
iGital inPut
This digital input can be used to receive information on the % of power to be supplied to the load.
The signal can be generated by a controller or external plc via digital outputs (logic output for Gefran instrumentation).
This is obtained by alternating the output in ON for time TON with the output in OFF for time TOFF.
The sum of TON+TOFF is constant, and is called CycleTime.
CycleTime= TON+TOFF
The power level is given by the ratio = TON/ CycleTime and is normally expressed in %.
The GTF digital input automatically adapts to the cycle time from 0.03Hz to 100Hz and obtains the power % to be
supplied to the load from the TON/(TON+TOFF) ratio.
Connection example:
Temperature control with Gefran 600 with D type logic output (out2) (cycle time: 0.1sec), logic output can drive max
3 GTF in series (preferable), connection allowed only if GTFs do not have interconnected GNDs (if so, make parallel
connection).
To use Digital PWM the GTF can be ordered with the configuration 5 -x - M or must be configured with the parameter
dIG (digital input) = 7 (see Fig. 28).
Figure 28
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