Hi Gerd,
Thanks heaps for the fast respone.
I havent been able to understand Ziegler-Nichols approach and have been starting the process at 100 for the proportional gain and trying to alter it to get a steady oscialtion around the desired point, this was working from postion control but speed is different.
Good to note PWM is usually between 0-100, it may be worth me using the duty cycle then instead of trying to change the high time of the pulse.
I didn't attach the VIs as the layout is messy but when I am on that computer next I will attach them. I think I don't have a good understanding of the topic and this is causing me the most frustration.
Thanks,
Kyle