I/O Terminal /
ERROR HANDLING AND DIAGNOSIS
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8.2.3 Reaction to PROFIBUS Error
A PROFIBUS error (failure of the master, withdrawal of the PROFIBUS plug etc.) is detected
after the DP watchdog has elapsed (usually in the region of 100 ms, unless this has been
deactivated in the master) or by bus timeout (the baud rate supervision time is set to 10 s).
The reaction at the output data of the coupler can be set in the UserPrmData:
Byte
Bit
Value
Description
00
bin
Reaction to PROFIBUS error: Standard-Bus cycle is
abandoned (default, digital outputs become 0, complex
outputs are set to a planned substitute value)
01
bin
Reaction to PROFIBUS error: Standard-Bus outputs become
0
10
0-1
10
bin
Reaction to PROFIBUS error: Standard-Bus outputs remain
unchanged
8.3 Standard-Bus
Diagnostic
This section describes the standard-bus diagnostic for the I/O device.
8.3.1 Standard-Bus
Interruption
If the Standard-Bus is interrupted, or suffers from a relatively long malfunction, the coupler
enters the Standard-Bus error state. Depending on the setting made for Reaction to
Standard-Bus error in the UserPrmData, the coupler abandons DP data exchange and sets
the Stat_Diag bit in the diagnostic data at the next DP start-up (with the consequence that DP
data exchange is not carried out), sets the DP inputs to 0, or leaves the DP inputs
unchanged.
Byte
Bit
Value
Description
00
bin
Reaction to Standard-Bus error: DP data exchange is
abandoned (default)
01
bin
Reaction to Standard-Bus error: DP inputs set to 0
10
2-3
10
bin
Reaction to Standard-Bus error: DP inputs remain unchanged
When the interruption or malfunction on the Standard-Bus has been rectified, the setting of
Response to Standard-Bus error in the UserPrmData determines whether the Standard-Bus
error state is left manually (by means of a Standard-Bus reset), or automatically:
Byte
Bit
Value
Description
0
bin
Response to Standard-Bus error: manual Standard-Bus reset
(default)
7
0
1
bin
Response to Standard-Bus error: automatic Standard-Bus reset