Siemens SIMATIC NET S7-300 User Manual

7 Programming FCs (Functions) and FBs for S7 Ethernet CPs
A-250
S7-CPs for Industrial Ethernet Configuring and Commissioning
Release 01/2007
C79000-G8976-C182-07
Example
In a normal situation (depending on the total length of the IO data), the block will
run over several user program cycles until the condition code DONE/NDR = 1 is
signaled.
Call the PNIO_RECV block until NDR = 1
Check the IOPS status of the received data (from the
PNIO devices) and, if necessary, start error handling
Edit and process data, prepare new output data
Call the PNIO_SEND block until DONE = 1
Check the IOCS status values received from the PNIO
devices and, if necessary, start error handling
Note: The user program cycle and the cycle of the IO data exchange between the
PNIO controller and PNIO devices are independent of each other.
7.8.5 Substitute Values
The setting of substitute values is supported for the two following operational
situations:
 Substitute values during startup (operating mode change on the CPU from
STOP to RUN
 Substitute values if problems are detected (remove/insert or station
failure/return)
Substitute Values during Startup
You can initialize the outputs with substitute values by setting a memory bit
(“start-up” memory bit) in the start-up OB. In cyclic mode (OB1), evaluate this
“start-up” memory bit to call the PNIO_SEND block with the initialization values
when appropriate.

Siemens SIMATIC NET S7-300 Specifications

General

Product Type Designation	SIMATIC NET S7-300
Mounting	DIN rail mounting
Protection Class	IP20
CPU Models	Various models available (e.g., CPU 312, CPU 314)
Communication Interfaces	MPI, PROFIBUS DP
Power Supply	24 V DC power supply required. Different power supply modules available.
I/O Modules	Digital input modules, digital output modules, analog input modules, analog output modules
Programming	STEP 7 software
Supply Voltage	24V DC or 120/230V AC (depending on model)
Digital Inputs	Available via digital input modules
Digital Outputs	Available via digital output modules
Analog Inputs	Available via analog input modules
Analog Outputs	Available via analog output modules
Communication Functions	MPI, PROFIBUS DP, Ethernet (depending on model)
Protocols	MPI, PROFIBUS DP, TCP/IP (depending on model)
Operating Temperature	0°C to 60°C
Storage Temperature	70 °C
Memory	Depends on CPU model (e.g., 32 KB to 1.5 MB)