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80999D_MHW_GFW 400-600A_07-2020
_ENG
3.9
d
igital
input
(pwm)
This digital input can be used to receive information on the % of power to be supplied to the load. (refer to the SW Manual for
configuration of the digital input).
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 GFW digital input INDIG1 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:
NOTE: for inputs INDIG2 and INDIG3, the maximum PWM frequency is limited to 1Hz, and INDIG4 cannot be configured as a PWM
input
Temperature control with Gefran 600 with D type logic output (out2) (cycle time: 0.1sec),
Figure 52
1
2
3
4
5
6
7
8
+
+24V
-
+ -
INDIG1 PWM IN
GND
Controller
Logic output
D type
