Siemens TC12 사용자 설명서

 

TC12 Installation, Commissioning & Maintenance Handbook 

LEDs are provided on the front edge of the board to provide basic status 
information. The position of these LEDs and their functions are shown in Figure 
30. 
 
The +5 V LED should be on.  
 
If the system fail LED is on, information about the type of fault that has occurred 
can be accessed using a handset terminal (see section 3.3.3.27 on handset 
commands).  

Note:   the OTU may still be operating normally, even with the system fail LED 

on, depending on the type of failure that has been detected. 

 
If the Watchdog fail LED is illuminated the software is not running correctly. All 
transmission from the OTU will be halted and all relay outputs will be set to their 
de-energised state. The only way to reset the board is to power off and then on 
again. 
 
The Transmit confirm LED is on whilst correctly formatted control messages are 
being received by the OTU, and the information is being transferred to the relay 
outputs. If a valid control message is not received for four seconds the transmit 
confirm LED will go out. Note this LED does NOT indicate that a reply message 
has been sent. 
 
The Carrier detect / Rx Data LED should come on once a second for each control 
signal on the line. For modem systems this LED indicates carrier is detected on 
the line. For RS232 systems where carrier is not required (see GRX command) 
the LED indicates data is being received. It does not indicate that the OTU 
received a valid control message.  
 

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