Siemens BACNET 125-699 - Manual (Page 37)

Troubleshooting
Siemens Building Technologies, Inc. 29
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. If one of the
following conditions occurs, the controller will activate safety features present in its fail-safe
mode.
• Sensor failure.
• Loss of power. Upon controller power loss, communication with the controller is also
lost. The controller will appear as failed (
*F*
) at the 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 eleven 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.