Siemens SIMATIC S7 - Page 34

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SM 338 Equipment Manual
(4) J31069-D401-U1-A0-7618
4.3.2 Channel-Related Diagnosis Bytes
Channel-related data are stored in bytes 4 to 11. The contents of bytes 4 to 6
are fixed while bytes 7 to 11 contain the actual channel errors.
Channel type =7E
H
7 0
0
Byte 4
1111110
Length of the diagnosis information
per channel
= Number of bits per channel
Value: 08
H
7 0
00010000
Byte 5
Number of channels (i.e., sensors)
Value: 04
H
7 0
00100000
Byte 6
Group error for channel 1
See byte 8 for more details.
7 0
0000
Byte 7
Group error for channel 2
See byte 9 for more details.
Group error for channel 3
Seebyte10formoredetails.
Group error for channel 4
See byte 11 for more details.
Channel type
Diagnosis bits per
channel
Number of
channels
Group errors of
the channels
(channel error
vector)
D
a
t
a
Communic
a
tion with the PLC