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Author Topic: 8 VOLT PWM SIGNAL  (Read 6741 times)

CMS

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8 VOLT PWM SIGNAL
« on: May 07, 2007, 09:03:18 PM »
Hi

Can the T100MX ( opto inputs ) handle a 8 Volt PWM signal at 500 hz.      Is the 8 volt enought to trigger the input??

Thankyou
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support

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Re:8 VOLT PWM SIGNAL
« Reply #1 on: May 08, 2007, 07:23:11 AM »
The spec is 9V minimum but 8 volt could be just about sufficient to turn on the T100MX+ optoisolated inputs. In the worst case scenario you can solder in parallel a resistor to the current limiting resistor onboard the PLC to increase the sensitivities.

500  Hz PWM signal is not a problem. You can use the PULSEWIDTH and PULSEPERIOD function to accurately measure the duty cycle of the PWM inputs.

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Dogface

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Re:8 VOLT PWM SIGNAL
« Reply #2 on: May 08, 2007, 07:38:51 AM »
Another alternative is to use a high speed switching transistor.

8volt signal through a 500KOhm resistor into the base.  Collector tied into the PLC input. The emitter tied into ground.

Works like a charm.
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