Hi. I believe it means to set your fax to call the other fax and request that it sends you the document which has been left in it for you. (Does that make sense?) But I'm not 100% sure, and I cannot find any source to confirm this.
That's correct Alfrif. A document is scanned into Fax A and held in memory until Fax B calls it ("polls" it) at which point Fax A transmits the saved document to Fax B. Fax B has a unique ID which must be submitted in order to release the document. What the use of this is, I do not know.
I guess the term "poll" is loosely borrowed from the word meaning "an inquiry into public opinion conducted by interviewing a random sample of people".
"Poll" is used routinely in the data communications world.
Point A polls point B either to see if it is there and working or to see if it is there and has anything it wishes to send to point A.
If fifty people have to send me a fax every night there are (at least) two ways this could be done. Each of their fax machines could keep on trying until they find mine available, then transmit; or theirs could be set to transmit on request and mine could be told to "poll" each of them in order.