Transportation problem in networknode

hey everyone:
I have big problem，just like the modle.
I hoped one car enters the NN6 unloading and the other cars where waiting in NN5，
When item after P7 and the P8 processing finish，
Lets the next car which NN5 waits enter again.

Now，i can let the cars waiting in NN5,but when item processing finish,the next car is unable to enter.

Could anyone help me to solve this problem??

To use this open/close gate approach, I'd suggest setting the capacity of NN5 to 1; make the paths non-passing, and set the travellers to Block Space on the network. Then use closenodeedge(current,1) in the OnContinue of NN5 and use opennodeedge(current,1) in the Message trigger.