Alarm, error, and system messages
12.2 Introduction to the BIOS beep codes
SIMATIC HMI IPC677C
164
Operating Instructions, 04/2013, A5E02722710-04
12.2
Introduction to the BIOS beep codes
The device performs a self-test when it is switched on. If an error is detected during the
POST (Power On Self-Test), a series of beep signals are issued. The beep tones are a code
for errors and are composed of 2 x 2 sequences.
Table 12- 1 Converting the beep codes in a Hex display
Beep tones
Hex code
B
B
0
B
BB
1
B
BBB
2
B
BBBB
3
BB
B
4
BB
BB
5
BB
BBB
6
BB
BBBB
7
BBB
B
8
BBB
BB
9
BBB
BBB
A
BBB
BBBB
B
BBBB
B
C
BBBB
BB
D
BBBB
BBB
E
BBBB
BBBB
F
Example
Tone sequence
B
BBB
BBB
B
Hex code
2
8
Meaning
Determine RAM size
12.3
BIOS beep codes
The following section lists the POST codes relevant to users in the sequence in which they
occur: Contact Customer Suppoinformation on all other POST codes.
Display
(hex)
Meaning
Description
Remedy
4DH
DXE_MTC_INIT
MTC Initial
MonoTonicCounter
initialization
Service case
4EH
DXE_CPU_INIT
CPU Middle
Initial
CPU initialization
Replace basic
module