Instruction manual

Page 29
Page 29 of 74 UTY4422-001
SECTION 3
OPERATION
3.1 MODES OF OPERATION
3.1.1 Power Up
At power up, the unit does a quick checksum test on the EEPROM. If the test passes, the unit
then initializes various devices and configures itself according to the EEPROM settings. It then
waits for the receiver board to complete its boot-up. When the receiver board boots up, the IRD
sends a tune request to the receiver board and the Welcome Banner to the serial port. The IRD
then enters alarm mode until all of the alarm conditions are cleared. Total boot-up time is
approximately 25 seconds, but may vary somewhat.
Also, while in power up mode, each of the Unity 4422’s LED's will FLASH (See Table 14,
Page 30.).
3.1.2 Boot Fail
If any of the boot fail conditions occur, the unit will enter “boot fail” mode. While in this mode,
the unit is essentially dead. All audio and video is muted, the alarm relay is closed, the general
purpose relays are all open, and the unit does not attempt carrier acquisitions, etc.
3.1.3 Alarm, Warning, & Normal
See Sections 3.2.7 and 3.2.8 for a complete list of alarm/warning conditions and for information
on the LED's during these modes. The overall behavior of the IRD is very similar for any of
these modes, and the following is a list of their differences:
• Alarm and User Relays. See Section 3.3 for details.
• Video is alarm frozen if No MPEG Data for less than 5 seconds, No Video for less than five
seconds, or in fade mode for less than 10 seconds.
• Video is muted for all alarm conditions except Alarming Eb/No.
• Audio is muted for all alarm conditions except Alarming Eb/No and No Video Data.
• LED's are unique for each of these modes.