Siemens SIMATIC S7-300 Module data Hardware And Installation Manual

Commissioning
S7-300 Programmable Controller Hardware and Installation
A5E00105492-01
8-27
Startup of CPU 31x-2 DP/31xC-2 DP as DP Master
On startup, CPU 31x-2 DP/31xC-2 DP compares the preset configuration of your
DP master systems to the actual configuration.
If preset configuration = actual configuration the CPU switches to RUN mode.
If the preset configuration ≠ to the actual configuration, the configuration of
parameter Startup if preset configuration ≠ actual configuration determines the
Startup behavior of the CPU.
Startup with preset configuration ≠ actual
configuration = yes (Default setting)
Startup with preset configuration ≠ actual
configuration = no
CPU 31x-2 DP/31xC-2 DP switches to RUN
mode.
(BUSF LED flashes if any of the DP slaves
cannot be addressed)
CPU 31x-2 DP/31xC-2 DP remains in STOP
mode. On expiration of the Monitoring time
for parameter transfer to modules the
BUSF LED starts flashing.
The flashing BUSF LED indicates that at
least one DP slave cannot be accessed. In
this case, check whether all DP slaves are
switched on or correspond with your
configuration, or read out the diagnostic
buffer with STEP 7.
Recognizing the operating state of DP Slaves (Event recognition)
The table below shows how CPU 31x-2 DP/31xC-2 DP as DP master recognizes
operating mode transitions of a CPU as DP slave or data exchange interrupts.
Table 8-8 Event recognition by CPUs 31x-2 DP/31xC-2 DP operating as DP master
Event What happens in the DP master?
Bus failure interrupt
(short-circuit,
connector
unplugged)
• Call of OB86 with the message Station failure
(coming event; diagnostic address of the DP slave assigned to
the DP master)
• with I/O access: Call of OB122
(I/O access error)
DP slave:
RUN → STOP
• Call of OB82 with the message Module error
(incoming event; diagnostic address of the DP slave assigned to
the DP master; Variable OB82_MDL_STOP=1)
DP slave:
STOP → RUN
• Call of OB82 with the message Module OK
(outgoing event; diagnostic address of the DP-Slave assigned to
the DP master; Variable OB82_MDL_STOP=0)
Tip:
When commissioning the CPU as DP master, always program OB 82 and 86. This
helps you to recognize and evaluate data exchange errors or interruption.

Siemens SIMATIC S7-300 Module data Specifications

General

Series	S7-300
Manufacturer	Siemens
Protection Class	IP20
System	SIMATIC S7-300
Digital Inputs	Varies by module
Digital Outputs	Varies by module
Analog Inputs	Varies by module
Analog Outputs	Varies by module
Central Processing Unit	Varies by CPU model
Supply Voltage	24V DC or 120/230V AC
CPU Type	Varies (e.g., CPU 312, CPU 315, etc.)
Memory	Varies by CPU model
Communication Interfaces	MPI, PROFIBUS
Programming Languages	LAD, FBD, STL, SCL, GRAPH
Operating Temperature	0°C to 60°C
Storage Temperature	-40°C to 70°C
Relative Humidity	10% to 95% (non-condensing)