Exactly which signal was used to track Sisko?

Question

A continuation of this question. In the end of Waltz episode

Sisko is rescued by Defiant after Defiant received a location or distress call from planet surface. It is said that it was Gul Dukat's signal, that Defiant received.

How it is possible?

Dukat destroyed its own distress-transmitting equipment in the middle of this episode. And since he escaped on-board Federation roundabout, then he must use its communication systems to transmit a location signal. Defiant crew wasn't familiar with events happening on planet's surface. And thus, how did they managed to say, that Dukat signal was used?

Answer 1

The quote from the original script is

O'BRIEN: (off console) Captain. I'm picking up a signal... (turns in surprise) It's from Gul Dukat.

Since the signal was evidently visual in origin (hence O'Brien seeing it on his comms console), presumably it was actually a written message transmitted on a Federation channel.

["This is Gul Dukat, your captain is at coordinates x, y, z on the following planet"]