Cisco Headend Digital Broadband Delivery System 维护手册
Appendix A
Bootloader LED Error Codes
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4024836 Rev D
Bootloader Error Codes for Single-LED DHCTs
Low-level bootloader error codes on the single-LED DHCT display if there is an
error condition detected by the bootloader when the DHCT boots, or when it loads
or installs software.
The DHCT displays the error code between a series of 4 illuminations. Before the
The DHCT displays the error code between a series of 4 illuminations. Before the
DHCT displays the error code, it will blink 4 times, then display the error code, then
blink 4 times, etc.
4 blinks, [error code] 4 blinks, [error code] 4 blinks, etc.
Note: The error code can display as many as 10 times.
Reading Bootloader Error Codes on the Single-LED DHCT
Error codes are displayed by the DHCT LED as a series of bright and dim
illuminations, which correspond to the ones and zeros of a binary code. The bright
illuminations represent 1 (or 'on') digits, and the dim illuminations represent 0 (or
'off') digits. The binary code is displayed by the DHCT from left (most-significant
bit) to right (least-significant bit).
The LED is located on the face of the DHCT.
Example: The binary code 0100 0001, representing a hexadecimal value of 0x41, is
read as one dim illumination followed by one bright illumination, followed by five
dim illuminations, and finally one bright illumination.
Important: You might not be able to distinguish a 'space' between consecutive dim
Important: You might not be able to distinguish a 'space' between consecutive dim
or bright illuminations. However, the relative time for each illumination is the same.
Therefore, two illuminations take twice as long to display as a single illumination.