Dynamic activation of communication channel

Is it possible to activate the file sender adapter  dynamically through BPM?

The scenario is as follows:

A file will have to be picked up by the sender file adapter but only when a particular BPM process is triggerred by another sender system. I am currently having the triggerring system's message received by a receiver file adapter and simultaneously executing a command to rename the file so that it is picked up by a constantly polling sender file adapter. I want to avoid the constant polling (1 sec or less) if it is possible to leave the adapter inactive and 'activate' it only when the BPM starts by the triggering message.