Siemens 125-5033 - Manual (Page 29)

Troubleshooting
Siemens Building Technologies, Inc. 21
Safety Features
The controller board stores the controller's address, applications, and point values. In the
event of a power failure or a reset, these values are retrieved from the controller’s permanent
memory and are used by the controller unless overridden by a field panel.
Controller LEDs
To determine if the controller is powered up and working, verify that the Basic Sanity Test
(BST) Light Emitting Diode (LED) is flashing ON/OFF once per second. The controller
contains six LEDs located on the circuit board. See the Controller LED lndicators section of
Chapter 1, Product Overview for more information about LEDs.
NOTE: The TX and RX LEDs indicate communication over the FLN.