Which code is used for Exit push button stick repeater relay?

• A. X
• B. XS
• C. ZE
• D. ZX

Answer: (B)

In signaling diagrams, equipment is labeled with codes that capture both the device type and any modifiers. The base symbol X stands for an Exit push button. When a stick repeater relay is involved, a suffix S is added to indicate that feature. So the combination XS identifies an Exit push button equipped with a stick repeater relay, meaning the push button’s action is repeated at another point in the system for visibility or control.

This specific XS label is used to distinguish it from a plain exit push button (which would just be X) or from other devices that use different suffixes or prefixes. The other codes don’t convey the same exact combination of exit push button plus stick repeater relay, so XS is the correct match.