What does the "Enable" pin do on the PCO-6141
A TTL high level on pin 10 (enable/disable) causes current to flow in an internal loop, but the current is shunted around the output.
Note that when enabled, the PCO-6141 dissipates a lot of power if a large current is programmed. To reduce heating, turn off the enable when the pulser is idle.
You can connect an interlock or key switch to the enable input to guard against unauthorized persons turning the output on.