# Example: network_operation_stop

> Note

> You can launch an interactive, editable version of this example without installing any local files using the Binder service (although note that at some times this may be slow or fail to open):

Example: Using `network_operation()` to stop a simulation. This script demonstrates how to use `network_operation()` to stop a simulation when a group of neurons reaches a target number of spikes.

    from brian2 import *

    N = 10
    tau = 10*ms
    I = 1.5
    target_spikes = 20

    G = NeuronGroup(N, 'dv/dt = (I - v)/tau : 1', threshold='v>1', reset='v=0', method='exact')
    G.v = 'rand()'

    spike_mon = SpikeMonitor(G)

    @network_operation(dt=1*ms)
    def check_spikes():
        if spike_mon.num_spikes >= target_spikes:
            print(f"Stopped at t={defaultclock.t} with {spike_mon.num_spikes} spikes")
            stop()

    run(100*ms)

    plot(spike_mon.t/ms, spike_mon.i, '.k')
    xlabel('Time (ms)')
    ylabel('Neuron index')
    title('Spike raster plot')
    show()