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USC-3 Manual > Booting and Settings > Signals During Booting

Signals During Booting 		Previous pageReturn to chapter overviewNext page

led

Figure 25: LED indicators

During the process of booting, the yellow LED (FA) is blinking at first (with ~3 Hz, once booted flickering occurs during data transfer), when finished, the green LED (OP) is blinking. If booting is finished, the green LED is steady on and the yellow LED is off. In addition, USC-3 OK (pin 14 on the 40 pin Extension connector) is set to high once the booting process is finished.

The following error cases can occur:

Error Case

possible Solution

All LEDs light weakly

Check the microSD card. Insert the card correctly.

All LEDs light up

Check whether the RS232 pins are shorted.

yellow LED does not start blinking

Is the blue LED (power supply) on? Check the power supply of the card and repower the card.

yellow LED does not stop blinking

Try to repower the card.

Make a copy of the SD card image.

green LED does not start blinking

Make a copy of the SD card image and check the yellow LED.

green LED  is blinking with low frequency

This indicates that the CPU crashed. Try to repower the card.

green LED is blinking with high frequency

This indicates a problem during booting. Try to repower the card.

Check the messages in the USC Server, or in the sc_usc_server_log.txt file for boot error.

Table 31: Error Case

During the booting process, following outputs will go into tri-state:

•Laser_Gate

•Laser_A

•Laser_B

•Laser_Port

•Digi_Outs

•Stepper_Outs

warning

Make sure that all these signals with tri-state go into a safe state (inactive), if needed by using a appropriate pull-up or pull-down resistor. The resistor should not be placed directly at the USC card but on the opposite side of the cable which connects the USC card to the respective device. This assures further safety in case the cable is somehow damaged. Please find further information in chapter Laser.

Usually, the booting process of the USC-3 takes about 15 seconds. The end of the booting process can also be checked by the help of USC-3_OK (pin 14 of the Extension connector) or by sending a signal via software to the USC-3 card and waiting for the reply indicating that the booting is finished (e.g. FCI command GCS).

note

If all LEDs turn on and stay on (instead of the usual blinking), maybe the SD card image needs to be updated or the battery of the USC-3 needs to be replaced (Hardware Revision 1.3, only).