Siemens SIMATIC NET S7-300 User Manual

7 Programming FCs (Functions) and FBs for S7 Ethernet CPs
A-185
S7-CPs for Industrial Ethernet Configuring and Commissioning
Release 01/2007
C79000-G8976-C182-07
7.2 Setting Parameters for FC Calls
Before describing the FCs in detail, a few general comments on calling and setting
parameters for FCs will be useful at this point.
It is possible to make the following general statements about the following
parameter groups that occur in all FCs:
 Parameters for CP and connection assignment (input parameters)
 Parameters for specifying a CPU data area (input parameters)
 Status information (output parameters)
Calling Communication Blocks for an S7-300
Caution
The communication blocks for S7-300 (SIMATIC NET block libraries for S7-300 in
STEP 7) must not be called in more than one priority class! If, for example, you
call a communication block in OB1 and in OB35, block execution could be
interrupted by the higher-priority OB.
If you call blocks in more than one OB, you must write your program so that a
communication block that is currently executing cannot be interrupted by another
communication block (for example by disabling/enabling SFC interrupts).
7.2.1 Parameters for CP and Connection Assignment (input
parameters)
When you call an FC, you transfer the module start address of the Ethernet CP in
the CPLADDR or LADDR parameter. The module start address of the Ethernet CP
can be found in the properties dialog of the CP in the “Address/Input” tab (can be
selected in the SIMATIC Manager or in HW Config).
With connection-oriented jobs, you must also reference the connection to be used
by its connection ID. You will find this in the properties dialog of the connection
under “Block parameters” (refer to the information in NetPro).

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)