Programming FCs (Functions) and FBs for S7 Ethernet CPs

5.3FCs for Configured Connections

Overview

The following functions (FCs) are available for transferring data over configured connections:

FC

Can be used with 1)

Meaning

 

S7 – 300

S7 – 400

 

 

 

 

 

AG_SEND (FC5)

x

x

for sending data

 

 

 

 

AG_RECV (FC6)

x

x

for receiving data

 

 

 

 

AG_LSEND (FC50)

 

x

for sending data

 

 

 

 

AG_LRECV (FC60)

 

x

for receiving data

 

 

 

 

1)Notes on the FCs in FCs for an S7-300 and S7-400 S S7-300:

With older versions of the Ethernet CPs, the data length per job is restricted to <=240 bytes (applies up to block version V3.0 of AG_SEND / AG_RECV); with later versions, longer data records (up to 8092 bytes) can be transferred with FCs AG_LSEND or AG_LRECV.

With the latest versions of the Ethernet CPs, only FCs AG_SEND and

AG_RECV are used; due to a new and more efficient internal protocol, the data up to 8092 bytes can be transferred.

SS7-400:

With FCs AG_SEND / AG_RECV the data length per job is restricted to <=240 bytes.

Longer data records (up to 8092 bytes) can be transferred with FCs AG_LSEND or AG_LRECV.

Please check the manual /3/ of the S7-CP you are using for the data areas supported. You will find an overview of the versions of the FCs/FBs in the documentation and block history.

Application

The following diagram illustrates the use of the FCs described here for bi-directional data transfer on one configured connection.

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SIMATIC NET NCM S7 for Industrial Ethernet

C79000-G8976-C129–06

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Image 148
Siemens S7 appendix FCs for Configured Connections, Can be used with Meaning

S7 specifications

The Siemens S7 series represents a cornerstone in the realm of programmable logic controllers (PLCs), developed by Siemens, a leading company in industrial automation. Widely used across various industries, the S7 series offers robust solutions for controlling machinery and processes, thanks to its reliable performance, flexibility, and scalable architecture.

One of the key features of Siemens S7 PLCs is the modularity of their design. Each system can be configured to meet specific application requirements due to the ability to mix various input/output modules, CPUs, and communication processors. This modular approach allows for the customization of systems to suit diverse automation tasks, providing end users with the adaptability required for modern manufacturing environments.

The S7 series encompasses several models, including the S7-1200, S7-300, and S7-1500. The S7-1200 is particularly suited for small to medium-sized applications, offering a compact design and integrated communication interfaces. In contrast, the S7-300 is designed for more extensive and complex control systems, making it ideal for large-scale industrial applications. The S7-1500 stands out with its advanced performance metrics, rich feature set, and high-speed processing capabilities, making it perfect for demanding applications that require real-time control and extensive data handling.

Siemens also emphasizes the importance of communication technologies within the S7 series. With options such as PROFINET, PROFIBUS, and EtherNet/IP, the S7 PLCs can seamlessly integrate into existing automation infrastructures, ensuring smooth data exchange between devices. The incorporation of web-based technologies and cloud connectivity further enables remote monitoring and control of systems, enhancing operational efficiency.

Another notable characteristic of Siemens S7 PLCs is the use of TIA Portal (Totally Integrated Automation Portal), an innovative software platform that simplifies the engineering process. TIA Portal allows users to program, configure, and diagnose their automation devices in a single environment, reducing setup times and improving productivity.

In conclusion, the Siemens S7 series stands out due to its modular design, range of models suitable for various applications, advanced communication technologies, and user-friendly programming software. This combination of features and characteristics makes S7 PLCs a preferred choice for industries seeking reliable and efficient automation solutions. As industrial demands continue to evolve, Siemens S7 PLCs remain at the forefront, adapting to technological advancements and setting benchmarks in the automation field.