Most of the posts above are referring to gate-lines on secondary entrances / exits, with a remote connection to the staff at the main gate-line.
I don't know what the OP** had in mind, but my post (which they quoted there) referred back to a situation where the *only* gate-line at a (London Underground) station was closed but unstaffed. It was suggested that I should have used a help point to gain access when my mag-stripe ticket failed to work the entry gate.
**Note, following some forum editing, that post is now no 4 in this thread.