Now works in a service on boot.

rrcs-trigger.service

@@ -0,0 +1,18 @@
+[Unit]
+Description=Runs the ras_pi_RRCS_BusyLight.py script at boot
+After=network.target
+#StartLimitIntervalSec=5
+
+[Service]
+Type=simple
+Restart=always
+RestartSec=5
+User=root
+ExecStart=/usr/local/bin/rrcs-trigger /usr/local/bin/ras_pi_RRCS_BusyLight.py
+WorkingDirectory=/tmp
+StandardOutput=journal
+StandardError=journal
+Environment=PYTHONUNBUFFERED=1
+
+[Install]
+WantedBy=multi-user.target