From cb824496aad651944ca480a030b41b8ff260b9a0 Mon Sep 17 00:00:00 2001
From: Michael Carroll <mjcarroll@intrinsic.ai>
Date: Fri, 3 Nov 2023 19:26:42 +0000
Subject: [PATCH] Add note about elevator example

Closes #2153

Signed-off-by: Michael Carroll <mjcarroll@intrinsic.ai>
---
 examples/worlds/elevator.sdf | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/examples/worlds/elevator.sdf b/examples/worlds/elevator.sdf
index f50ee17c59..0cbcd8702e 100644
--- a/examples/worlds/elevator.sdf
+++ b/examples/worlds/elevator.sdf
@@ -10,6 +10,12 @@
 
     gz topic -e -t /model/elevator/state
 
+  Note that when commanding the lift to the ground floor:
+
+    gz topic -t "/model/elevator/cmd" -m gz.msgs.Int32 -p "data: 0"
+
+  The output of the topic echo command will stop as protobuf does not
+  distinguish between the un-set value and zero for integer fields.
 -->
 <sdf version="1.6">
   <world name="elevator_world">