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S7-300 CPU 31x -- Product information -- Determining performance and quantity frameworks
How many connections and communication jobs do SIMATIC S7-300 and S7-400 support simultaneously?
Which connection resources are occupied in the S7-300 CPU for communication connections and services of the Industrial Ethernet CP?
What are the system limits in an F CPU for safe bidirectional data communication using S7 Communication?
How can you determine the size of the load memory and main memory of a SIMATIC S7-300/400 CPU?
What restrictions are there for active jobs when communicating with SFC 58 / SFC 59 and SFB 52 / SFB 53 via PROFIBUS DP and PROFINET IO?
Where do you find information on transmission times on the PROFIBUS or Industrial Ethernet?
What is a hardware interrupt and how do they work in the S7-300 system?
What is the maximum number of OPs that a CPU S7-300 can communicate with?
What can you do when the power requirement of the modules in the subrack exceeds the power supply provided by the CPU on the backplane bus?
Does PROFIBUS DP communication use connection resources?
What is the maximum number of CP modules that can be slotted in a SIMATIC S7-300/400 station?
Why, in the case of a networked SIMATIC S7, does the connection to the OP clear down when you call diagnostics functions with the PG or transfer blocks?
How many breakpoints can you insert when debugging a program?
S7-400 CPU 41x -- Product information -- Determining performance and quantity frameworks
How can you change the size of the available free main memory of a SIMATIC S7-400 CPU?
How many connections and communication jobs do SIMATIC S7-300 and S7-400 support simultaneously?
Which connection resources are occupied in the S7-400 CPU for communication connections and services of the Industrial Ethernet CP?
How many breakpoints can you insert when debugging a program?
What are the system limits in an F CPU for safe bidirectional data communication using S7 Communication?
How can you determine the size of the load memory and main memory of a SIMATIC S7-300/400 CPU?
Where do you find information on transmission times on the PROFIBUS or Industrial Ethernet?
What is a hardware interrupt and how do they work in the S7-400 system?
What restrictions are there for active jobs when communicating with SFC 58 / SFC 59 and SFB 52 / SFB 53 via PROFIBUS DP and PROFINET IO?
Industrial Ethernet S7-300/400 CPs -- Product information -- Determining performance and quantity frameworks
How many connections and communication jobs do SIMATIC S7-300 and S7-400 support simultaneously?
Which connection resources are occupied in the S7-300 CPU for communication connections and services of the Industrial Ethernet CP?
Which connection resources are occupied in the S7-400 CPU for communication connections and services of the Industrial Ethernet CP?
What are the system limits in an F CPU for safe bidirectional data communication using S7 Communication?
Where do you find information on transmission times on the PROFIBUS or Industrial Ethernet?
Increasing the CPU load for a data length of greater than 240 bytes in the case of Send/Receive communication with Industrial Ethernet CPs
What RAM capacity does the CP 343-1 IT make available for FTP services?
Why under certain circumstances are there very long response times with TCP connections?
ET 200S (standard modules) -- Product information -- Technical data
Which modules support the S7 routing function?
Which communication services supported by the CPUs with integrated PROFINET interface and by the WinAC RTX via Industrial Ethernet?
Which PROFIBUS connectors can you use in Zone 1 or 2?
What are the system limits in an F CPU for safe bidirectional data communication using S7 Communication?
Which SIMATIC S7 components and which drives support clock-synchronicity functionality?
ET 200S: Are there special requirements for ET200S when mounted on sheet metal plates?
ET200S: How many motor starters can be allocated to a power module?
ET 200S: How many motor starters can be allocated to a power module?
ET 200S: How many load feeders may be connected?
Calculating the maximum absolute error of the counter module 1Count24V/100kHz (6ES7 138-4DA02-0AB0) when measuring rotational speed
Implementation of SIMATIC modules of the product families S7-300, S7-400, ET 200M, ET 200S ET, 200iSP and TDC in environments with high concentrations of corrosive gas
Which transfer rates does the ET 200S interface module IM151-1 FO support over PROFIBUS DP.
Maximum power load for digital output modules
Minimum distance to the ET 200S front
How do you assign and identify thermocouples?
How long does the input signal have to be present before an analog input module identifies this signal as a process alarm?
WinAC RTX F -- Product information -- Determining performance and quantity frameworks
What new features do Intel® Atom™ processors have and what advantages do SIMATIC IPCs with Intel® Atom™ processors offer when used with SIMATIC software?
What are the system limits in an F CPU for safe bidirectional data communication using S7 Communication?
Why does the Windows application load increase to 100% after installing WinAC RTX 2008/2009?
What different CPU technologies are available in the PC sector and what are the advantages offered by SIMATIC PCs with Intel® Core™ 2 Duo processors when using SIMATIC software?
F Technology CPU 300/400 -- Product information -- Technical data
Where can you find images, graphics, symbols and screenshots for SIMATIC industrial automation systems?
What are the system limits in an F CPU for safe bidirectional data communication using S7 Communication?
How do you incorporate the execution times of the F blocks for the Mobile Panel 277F IWLAN into the "S7fcotia.xls" table?
Why does my F system go into STOP at startup?
Which values can you use with F CPUs and products of the ET 200 family for PFD, PFH and the proof test interval?
Which fail-safe signal modules of the distributed I/O can be combined with which fail-safe controllers?
Which hardware and software components are required to set up and operate an F system with SIMATIC S7-300F?
What are the system limits in an F CPU for safe bidirectional data communication using S7 Communication?
Part number:

Description
This entry gives you an overview of the system limits of S7 Communication.

The following figures show the basic configuration of S7 Communication between F CPUs over Industrial Ethernet. Bidirectional data communication is via an S7 connection.


Fig. 01

Alternatively, bidirectional data communication can be via two separate S7 connections. In this way, you can structurally separate the send and receive channels, for example.


Fig. 02

The system limit of S7 Communication is determined by the following parameters:

  • Max. number of connections supported by the CPU.
  • Max. number of S7 connections that can be configured per interface.
  • Max. number of instances supported by the CPU.

Max. number of connections supported by the CPU
The following table shows the maximum number of connections supported by the F CPUs.
 
F CPU Max. number of connections 
IM151-8F PN/DP CPU 12
IM154-8F PN/DP CPU 16
IM154-8FX PN/DP CPU 16
CPU 315F-2 PN/DP 16
CPU 317F-2 PN/DP 32
CPU 319F-3 PN/DP 32
CPU 414F-3 PN/DP V6 64
CPU 416F-2 DP 64
CPU 416F-3 PN/DP V5 64
CPU 416F-3 PN/DP V6 96
WinAC RTX F 2009 64
WinAC RTX F 2010 96

Max. number of S7 connections that can be configured
The following table shows the maximum number of S7 connections supported by the F CPUs.
 
F CPU Max. number of S7 connections that can be configured 
IM151-8F PN/DP CPU 10
IM154-8F PN/DP CPU 14
IM154-8FX PN/DP CPU 14
CPU 315F-2 PN/DP 14
CPU 317F-2 PN/DP 16
CPU 319F-3 PN/DP 16
CPU 414F-3 PN/DP V6 62
CPU 416F-2 DP with CP443-1 Adv. 62
CPU 416F-3 PN/DP V5 62
CPU 416F-3 PN/DP V6 94
WinAC RTX F 2009 Over CP5611: 6
Over CP5613: 48
Over CP1616: 30
Over IE general: 14
WinAC RTX F 2010 Over CP5611: 6
Over CP5613: 48
Over CP1616: 30
Over IE general: 14

Max. number of instances
The following table shows the maximum number of instances supported by the F CPUs.
 
F CPU Max. number of instances
IM151-8F PN/DP CPU 32
IM154-8F PN/DP CPU 32
IM154-8FX PN/DP CPU 32
CPU 315F-2 PN/DP 32
CPU 317F-2 PN/DP 32
CPU 319F-3 PN/DP 32
CPU 414F-3 PN/DP 300 (internal interface)
CPU 414F-3 PN/DP with CP443-1 Adv. 1200 can be configured (300 preset)
CPU 416F-2 DP with CP443-1 Adv. Firmware version < V5.2: 1800 can be configured (600 preset)
Firmware version V5.2 onwards: 4000 can be configured (600 preset)
CPU 416F-3 PN/DP 600 (internal interface)
CPU 416F-3 PN/DP with CP443-1 Adv. Firmware version < V5.2: 1800 can be configured (600 preset)
Firmware version V5.2 onwards: 4000 can be configured (600 preset)
WinAC RTX F 2009 600 can be configured (300 preset)
WinAC RTX F 2010 4000 can be configured (600 preset)

Example
In a CPU 319F-3 PN/DP, you select S7 Communication over TCP/IP for safe bidirectional data communication. Depending on whether the data communication is with one or two configured S7 connections, you can configure another 15 or 14 S7 connections.

The fail-safe communication blocks "F_SENDS7" and "F_RCVS7" are called in the CPU user program for safe bidirectional data communication over S7 connections. These blocks internally call the system function blocks SFB8 "USEND" and SFB9 "URCV" respectively. In this way, the user data and associated acknowledgments are sent and received. An instance data block is assigned to each SFB8 "USEND" and SFB9 "URCV" system function block. Thus, the number of instance data blocks (= instances) is identical to the number of communication jobs.

This means that in the case of safe bidirectional data communication, at least four communication jobs are executed and four instances are needed. In this case, with the CPU 319F-3 PN/DP there remain 28 free instances.

In the user program of the CPU 319F-3 PN/DP, you can call a maximum of 16 fail-safe communication blocks "F_SENDS7" or F_RCVS7", because the maximum number of instances is limited to 32.
In the case of safe bidirectional data communication, the CPU 319F-3 PN/DP can communicate with a maximum of 8 F CPUs.

Calculation for safe bidirectional data communication in the CPU 319F-3 PN/DP
8  "F_SENDS7" + 8 "F_RCVS7" = 16 fail-safe communication blocks
8*("USEND" + "URCV") + 8*("USEND" + "URCV")
= 16 "USEND" + 16 "URCV" = 32 communication jobs or instances

Note
The safety function is foremost with F CPUs. Therefore, the system limit of S7 Communication is determined not only by the number of communication connections, but also by the response times achieved. If the required response times are not achieved because of the number of communication connections, the remedy is to

  • Reduce the number of communication connections.
  • Use a larger and faster CPU.

 Entry ID:38549114   Date:2013-07-22 
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