From my task loop I am sending a 0 or 5 signal to ‘PCI-6229 analog output’. Using a scope I can see that when a trial starts this changes to 5 and then gets reset to 0 so I am confident it is receiving the correct input. Through AO0 on the national instrument board I have attached a BNC lead which should trigger another piece of equipment (either TMS or a sound box). On most trials this works fine however every so often the A0o does not send an output… On these trials, the scope shows it received the correct value of 5 so it should have sen an output. I have tried using a differnet A0 port, a different BNC cable and different equipment to trigger and nothing helps so I am confident it is something to do with the ‘PCI-6229 analog output’ but I am just not sure what.