Recently there was a discussion on our Fieldbus User Network about control in the field. A user was wondering if they had to reduce the number of devices on a segment if they are using control in the field. The user's impression was that control in the field would increase overall network traffic and affect latency times, so the number of devices on a segment would have to be reduced. Actually, this is untrue. As you can see in the thread, fieldbus works better when you implement control in the field. "Your macrocycle will be less constrained and your PID will work better."
Fieldbus User Network Discussion on Control in the Field