Siemens S7 Series User Manual

1 Task
Communication with S7 CPU via KNX Gateway
Entry ID: 109739689, V1.0, 06/2017
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 Siemens AG 2017 All rights reserved
1 Task
1.1 Introduction
Gateways enable communication between two networks/bus systems that use
different communications protocols.
KNX is a fieldbus for building automation. Technically, KNX is the successor to the
European Installation Bus (EIB), adding communication mechanisms and
transmission media.
The functionality of a KNX system can be extended by integrating an S7 CPU into
a KNX system via a gateway. An S7 CPU enables the use of various functions and
statements for creating a control program and processing data.
The “LGF (Library of general functions)” for STEP 7 (TIA Portal) and S7-1200 / S7-
1500 additionally provides complementary functions such as an astronomical clock,
weekly timer, FIFO and many more (see \4\).
1.2 Overview of the automation task
The task is to establish, using a KNX gateway, a communication connection
between an S7 CPU via PROFINET (PN) and a KNX device via the KNX bus.
Each KNX device has a physical address (PA) via which the device can be
accessed. The individual functions of a KNX device are addressed by group
addresses (GA).
Through bidirectional data exchange between a KNX gateway and an S7 CPU,
signals of a KNX device are to be processed in the S7 CPU or KNX devices are to
be controlled using the S7 CPU.
The figure below provides an overview of the automation task.
Figure 1-1: Block diagram of the automation task
KNX devices
KNX
gateway
PROFINET
SIMATIC
CPU
KNX

Siemens S7 Series Specifications

General

CPU	Varies by model (e.g., S7-300, S7-400, S7-1200, S7-1500)
Memory	Varies by model (e.g., 64 KB to 20 MB)
Communication Interfaces	PROFINET, PROFIBUS, Ethernet, MPI
I/O Modules	Digital Input (DI), Digital Output (DO), Analog Input (AI), Analog Output (AO)
Programming	STEP 7 (TIA Portal) programming software. Supports various programming languages and provides tools for configuration, diagnostics, and commissioning.
Power Supply	24 V DC, 120/230 V AC. Integrated or external power supply, depending on the CPU and system configuration.
Operating Temperature	Typically 0 to 60 °C (horizontal mounting), -20 to 60°C (vertical mounting), depending on the specific module.
Product Type Designation	S7-300, S7-400, S7-1200, S7-1500
Programming Languages	LAD, FBD, STL, SCL, GRAPH
Digital Inputs	Varies by module (e.g., 8, 16, 32 channels)
Digital Outputs	Varies by module (e.g., 8, 16, 32 channels)
Analog Inputs	Varies by module (e.g., 2, 4, 8 channels)
Analog Outputs	Varies by module (e.g., 2, 4, 8 channels)
Operating Voltage	24V DC or 120/230V AC (varies by model)
CPU Processing Speed	Varies by model (e.g., 0.1 ms to 5 ns per instruction)
Real-time Clock	Integrated (varies by model)
Mounting Type	DIN rail mounting.
Protection Class	IP20