The Operating Instructions for the FP-PG-522 are located at the following link: http://digital.ni.com/manuals.nsf/websearch/BD4E654A16F5573986256838006CBE23?OpenDocument&node=132100_US
In Continuous Pulse mode, the channel is supposed to continuously pulse. However, it is possible to stop the pulses by changing the Off Time to 0. With an Off Time of 0, the channel will always be high. Please note that the Off Time can be between 0 and 65535 (inclusive) but the On Time is restricted to be between 1 and 65535 (inclusive). Thus it is not possible in Continuous Pulse mode to never have the channel pulse high and always stay low.
Regards,
Aaron
LabVIEW Champion, CLA, CPI