Siemens SIMATIC S5-90U System Manual page 106

Diagnostics and Trouble Shooting
Diagnostic Byte Assignment for the S5-95U
Interrupt at I 34.3
No interrupt at I 34.3
Interrupt at I 34.2
No interrupt at I 34.2
Interrupt at I 34.1
No interrupt at I 34.1
Interrupt at I 34.0
No interrupt at I 34.0
Battery backup available
Battery backup failure
Power supply failure for
onboard I/Os
Power supply for onboard
I/Os available
Counter overflow - counter B
No counter overflow - counter B
Counter overflow - counter A
No counter overflow - counter A
Note
The "Power supply failure for onboard I/Os" bit is set only if all power supplies listed
below have failed.
• Power supply for inputs 32.0 to 33.7 (PIN 1b Figure 3-22)
• Power supply for outputs 32.0 to 32.7 (PIN 1a Figure 3-22)
• Power supply for outputs 33.0 to 33.7 (PIN 11a Figure 3-22)
If at least one of the above mentioned supply voltages is present, the "Power supply
failure for onboard I/Os" bit is "0".
Interrupts and counter overflow is flagged in the diagnostic byte only if the interrupt
and counter inputs have been parameterized in DB1 (see Chapter 10 and 11).
5-2
Bit no.: 7
i
IB 35
3
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
Figure 5-2. Diagnostic Byte for the S5-95U
6 5 4 3 2
i i i B U
2 1 0
EWA 4NEB 812 6115-02b
S5-90U/S5-95U
1 0
CB CA