PWM is triggered when tmr2 = pr2
So If you use INT interrupt (B0) as Enamul suggested then you could place a C box with:
Within interrupt.
Then PWM will be forced to go high when signal changes on B0 from high to low or low to high depending on interrupt settings.
If PWM is already high when interrupt is triggered, then the PWM will remain high for the whole on duration.
E.g if PWM is normally high for 1ms, suppose pwm has been triggered 500us ago , then PWM will be high for a total of 1.5ms
Can you give more details e.g PWM frequency and duty.
target device & osc frequency.
All the details you can.
I guess you could alter the position of PWM by disabling timer2, wait until yo require triggering, then re-enable timer2 with again tmr2=pr2
to force PWM to go high.
Alternatively if a lower frequency is required for PWM than built in PWM can produce, then you would need to use bit bang method.
It should still be possible to sync with an external trigger signal
Martin