In my simulation, once a batch of 4 passes through the queue for just processed units, a new flow item of different type is to be released into the same queue and exit once the four units leave. What I have tried is using a global variable that increments by 1 for each unit that passes through the final processing queue and when the global variable is divisible by 4, trigger a source to release one unit of the new flow type. Let me know if this is in the correct realm of approaching the problem as I was still unsuccessful, mainly when it came to controlling the source releasing. I have attached a fresh version of my set up. For context, the processor alternates between the red and green units every 4 units.
Thank for the input!