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8.4.2.2
Enhanced diagnosis
Since the "Safety at Work" monitor diagnosis is longer than the maximum size of
the command interface, it must be read with several adjacent requests.
The byte 5 ('index') declares the start index in the array of diagnostic data. If this
start index is 0, the whole diagnosis is fetched from the monitor and stored to an
internal buffer. Otherwise, the AS-i Master will respond out of the internal buffer.
Thus, even though several requests are necessary to read the whole buffer, data
integrity is maintained.
byte
1
2
3
4
5
1. L=1 long diagnosis for advanced monitor
2. U=1 unsorted diagnosis (all devices)
byte
1
2
3
4
...
n
Subject to reasonable modifications due to technical advances.
102
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7
6
5
2
2
2
T
1
2
L
U
7
6
5
2
2
2
T
diagnosis byte #index+n-3
Request
4
3
2
2
7E
16
02
16
slave address
index
Response
4
3
2
2
7E
16
result
diagnosis byte #index+0
diagnosis byte #index+1
...
AS-Interface
Command Interface
2
1
2
2
circuit
2
1
2
2
Copyright Pepperl+Fuchs, Printed in Germany
0
2
0
2
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