103BCommunication
10.3 PROFIBUS
S7-1200 Programmable controller
System Manual, 11/2011, A5E02486680-05
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10.3.3
Distributed I/O Instructions
The following Distributed I/O instructions (Page 260) can be used with PROFIBUS:
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RDREC instruction (Page 260): You can read a data record with the number INDEX from
a component.
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WRREC instruction (Page 260): You can transfer a data record with the number INDEX
to a DP slave component defined by ID.
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RALRM instruction (Page 263): You can receive an interrupt with all corresponding
information from a DP slave component and supply this information to its output
parameters.
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DPRD_DAT instruction (Page 269): The CPU supports up to 64 bytes of consistent data.
You must read consistent data areas greater than 64 bytes from a DP standard slave with
the DPRD_DAT instruction.
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DPWR_DAT instruction (Page 269): The CPU supports up to 64 bytes of consistent data.
You must write consistent data areas greater than 64 bytes to a DP standard slave with
the DPWR_DAT instruction.
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DPNRM_DG instruction (Page 271): You can read the current diagnostic data of a DP
slave in the format specified by EN 50 170 Volume 2, PROFIBUS.
10.3.4
Diagnostic instructions
The following diagnostic instructions can be used with either PROFINET or PROFIBUS:
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GET_DIAG instruction: You can read the diagnostic information from a specified device.
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DeviceStates instruction: You can retrieve the operational states for a distributed I/O
device within an I/O subsystem.
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ModuleStates instruction: You can retrieve the operational states for the modules in a
distributed I/O device.
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LED instruction: You can read the state of the LEDs for a distributed I/O device.
10.3.5
Diagnostic events for distributed I/O
Note
With a PROFINET 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 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.