Diagnostics (Profinet Or Profibus); Diagnostic Instructions; Diagnostic Events For Distributed I/O - Siemens S7-1200 System Manual

8.5

Diagnostics (PROFINET or PROFIBUS)

8.5.1

Diagnostic instructions

The following diagnostic instructions can be used with either PROFINET or PROFIBUS:
● GET_DIAG instruction (Page 358): You can read the diagnostic information from a
● DeviceStates instruction (Page 347): You can retrieve the operational states for a
● ModuleStates instruction (Page 353): You can retrieve the operational states for the
● LED instruction (Page 346): You can read the state of the LEDs for a distributed I/O
8.5.2

Diagnostic events for distributed I/O

Note
With a PROFIBUS IO system, after a download or power cycle, the CPU will go to RUN
mode unless the hardware compatibility is set to allow acceptable substitute modules
(Page 142) and one or more modules is missing or is not an acceptable substitute for the
configured module.
As shown in the following table, the CPU supports diagnostics that can be configured for the
components of the distributed I/O system. Each of these errors generates a log entry in the
diagnostic buffer.
Table 8- 114 Handling of diagnostic events for PROFINET and PROFIBUS
Type of error
Diagnostic error
Rack or station failure
I/O access error
1
Peripheral access error
Pull / plug event
I/O access error example cause: A module that has been removed.
1
Peripheral access error example cause: Acyclic communication to a submodule that is not communicating.
2
Use the GET_DIAG instruction (Page 358) for each station to obtain the diagnostic
information. This will allow you to programmatically handle the errors encountered on the
device and if desired take the CPU to STOP mode. This method requires you to specify the
hardware device from which to read the status information.
S7-1200 Programmable controller
System Manual, 03/2014, A5E02486680-AG
specified device.
distributed I/O device within an I/O subsystem.
modules in a distributed I/O device.
device.
Diagnostic information for
the station?
Yes
Yes
No
No
2
Yes
8.5 Diagnostics (PROFINET or PROFIBUS)
Entry in the diagnostic
buffer?
Yes
Yes
Yes
Yes
Yes
Extended instructions
CPU operating mode
Stays in RUN mode
Stays in RUN mode
Stays in RUN mode
Stays in RUN mode
Stays in RUN mode
345