Internet PLC Forum
General => Technical support => Topic started by: CMS 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
-
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.
-
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.