Siemens SIMATIC NET CP 343-1 User manual

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SIMATIC NET
S7-300 - Industrial Ethernet /
PROFINET
CP 343-1
Manual
Manual Part B
12/2018
C79000−G8976−C201
-08
Preface
Properties / services
1
Performance data
2
Requirements for use
3
LEDs
4
Installation, connecting up
and commissioning
5
Configuration and operation
6
Service and maintenance
7
Technical specifications
8
Approvals
A
References
B

Siemens AG
Division Process Industries and Drives
Postfach 48 48
90026 NÜRNBERG
GERMANY
C79000−G8976−C201-08
Ⓟ
01/2019 Subject to change
Copyright © Siemens AG 2009 - 2018.
All rights reserved
Legal information
Warning notice system
This manual contains notices you have to observe in order to ensure your personal safety, as well as to prevent
damage to property. The notices referring to your personal safety are highlighted in the manual by a safety alert
symbol, notices referring only to property damage have no safety alert symbol. These notices shown below are
graded according to the degree of danger.
DANGER
indicates that death or severe personal injury will result if proper precautions are not taken.
WARNING
indicates that death or severe personal injury may result if proper precautions are not taken.
CAUTION
indicates that minor personal injury can result if proper precautions are not taken.
NOTICE
indicates that property damage can result if proper precautions are not taken.
If more than one degree of danger is present, the warning notice representing the highest degree of danger will
be used. A notice warning of injury to persons with a safety alert symbol may also include a warning relating to
property damage.
Qualified Personnel
The product/system described in this documentation may be operated only by
personnel qualified
for the specific
task in accordance with the relevant documentation, in particular its warning notices and safety instructions.
Qualified personnel are those who, based on their training and experience, are capable of identifying risks and
avoiding potential hazards when working with these products/systems.
Proper use of Siemens products
Note the following:
WARNING
Siemens products may only be used for the applications described in the catalog and in the relevant technical
documentation. If products and components from other manufacturers are used, these must be recommended
or approved by Siemens. Proper transport, storage, installation, assembly, commissioning, operation and
maintenance are required to ensure that the products operate safely and without any problems. The permissible
ambient conditions must be complied with. The information in the relevant documentation must be observed.
Trademarks
All names identified by ® are registered trademarks of Siemens AG. The remaining trademarks in this publication
may be trademarks whose use by third parties for their own purposes could violate the rights of the owner.
Disclaimer of Liability
We have reviewed the contents of this publication to ensure consistency with the hardware and software
described. Since variance cannot be precluded entirely, we cannot guarantee full consistency. However, the
information in this publication is reviewed regularly and any necessary corrections are included in subsequent
editions.

CP 343-1
Manual, 12/2018, C79000−G8976−C201-08 3
Preface
Legend:
①
LEDs
②
Under the front panel:
PROFINET interface, 2 x 8-pin RJ-45 jack
③
Under the front panel:
- Socket for 24 V DC power supply
- Slider for setting the ground connector
④
Article number
⑤
Under the front panel:
printed text with MAC addresses and firmware version
⑥
X = placeholder for hardware product version
Figure 1 CP 343-1
Validity and product names
This description contains information on the following product:
●CP 343−1
Article number 6GK7343-1EX30-0XE0
Hardware product version 7
Firmware version V3.0
Communications processor for SIMATIC S7−300 / C7−300 und SINUMERIK 840D power
line
●CP 343−1
Article number 6AG1343-1EX30-7XE0
Hardware product version 7
Firmware version V3.0
Communications processor for SIMATIC S7−300 / C7−300 und SINUMERIK 840D power
line - conformal coating

Preface
CP 343-1
4Manual, 12/2018, C79000−G8976−C201-08
Note
Names
•
In this document, the term "CP" is used instead of the full product name.
•
The name STEP 7 is used for the configuration tool instead of the names STEP 7 V5.5
and STEP 7 Professional.
New in this edition
New ATEX/IECEx approval
Replaced documentation
This manual replaces the manual edition 10/2012.
Innovations and compatibility with the predecessor product
Note
You will find the new functions of the module in the section
Enhanced functions (Page 11).
Make sure that you read the information relating to enhanced functions and restrictions in the
section
Module replacement / upgrading (Page 60).
Address label: Unique MAC address preset for the CP
The CP ships with a default MAC address. The MAC address is printed on the housing.
Address label: Unique MAC address for the CP
The CP is supplied with total of 3 default MAC addresses with the following assignment:
●PROFINET interface
●One MAC address for each of the 2 Ethernet ports of the PROFINET interface
The MAC addresses of the Ethernet ports are required only for detection and evaluation
of neighborhood and topology relations.
The MAC address of the PROFINET interface is printed on the housing.
If you configure a MAC address (ISO transport connections), we recommend that you use
the MAC address printed on the module for module configuration!
●This ensures that you assign a unique MAC address in the subnet!
●If you replace a module, the MAC address of the predecessor is adopted when you load
the configuration data; configured ISO transport connections remain operable.
You should also refer to the information in the section Replacing a module (Page 59).

Preface
CP 343-1
Manual, 12/2018, C79000−G8976−C201-08 5
Structure of the documentation
The documentation for this device consists of the following parts:
●Manual Part A: Configuration manual "Configuring and Commissioning S7CPs for
Industrial Ethernet", see references /1/ (Page 71).
●Manual Part B: Manual "CP 343-1" (this manual)
●Program blocks for SIMATIC NET S7 CPs - programming manual, see references /10/
(Page 73)
Contains the detailed description of the program blocks for the following services:
–Open communication services
–Access coordination with FETCH/WRITE
–Connection and system diagnostics
–Programmed connections and IP configuration
–PROFINET IO
Current manual release on the Internet
You will also find the current version of this manual on the Internet pages of Siemens
Automation Customer Support under the following entry ID:
Link: (http://support.automation.siemens.com/WW/view/en/24485272)
CP documentation in the Manual Collection (order no. A5E00069051)
The "SIMATIC NET Manual Collection" DVD contains the device manuals and descriptions
of all SIMATIC NET products current at the time it was created. It is updated at regular
intervals.
Version History / Current Downloads for the SIMATIC NET S7 CPs
The "Version History/Current Downloads for SIMATIC NET S7 CPs" provides information on
all CPs available up to now for SIMATIC S7 (Industrial Ethernet, PROFIBUS and IE/PB
Link).
An up-to-date version of this document can be found at on the Internet under the entry ID:
Link: (https://support.industry.siemens.com/cs/ww/en/view/109474421)
License conditions
Note
Open source software
The product contains open source software. Read the license condition
s for open source
software carefully before using the product.

Preface
CP 343-1
6Manual, 12/2018, C79000−G8976−C201-08
You will find license conditions in the following document on the supplied data medium:
●OSS_CP3431_86.pdf
Firmware
The firmware is signed. This ensures that only firmware created by Siemens can be
downloaded to the device.
Security information
Siemens provides products and solutions with industrial security functions that support the
secure operation of plants, systems, machines and networks.
In order to protect plants, systems, machines and networks against cyber threats, it is
necessary to implement – and continuously maintain – a holistic, state-of-the-art industrial
security concept. Siemens’ products and solutions constitute one element of such a concept.
Customers are responsible for preventing unauthorized access to their plants, systems,
machines and networks. Such systems, machines and components should only be
connected to an enterprise network or the internet if and to the extent such a connection is
necessary and only when appropriate security measures (e.g. firewalls and/or network
segmentation) are in place.
For additional information on industrial security measures that may be implemented, please
visit
Link: (http://www.siemens.com/industrialsecurity)
Siemens’ products and solutions undergo continuous development to make them more
secure. Siemens strongly recommends that product updates are applied as soon as they are
available and that the latest product versions are used. Use of product versions that are no
longer supported, and failure to apply the latest updates may increase customers’ exposure
to cyber threats.
To stay informed about product updates, subscribe to the Siemens Industrial Security RSS
Feed under
Link: (http://www.siemens.com/industrialsecurity)
FAQs on the Internet
You will find detailed information (FAQs) on using the CP described here on the Internet at
the following address (entry type "FAQ"):
Link: (http://support.automation.siemens.com/WW/view/en/10806067)
SIMATIC NET glossary
Explanations of many of the specialist terms used in this documentation can be found in the
SIMATIC NET glossary.
You will find the SIMATIC NET glossary on the Internet at the following address:
50305045 (http://support.automation.siemens.com/WW/view/en/50305045)

Preface
CP 343-1
Manual, 12/2018, C79000−G8976−C201-08 7
Recycling and disposal
The product is low in pollutants, can be recycled and meets the requirements of the WEEE
directive 2012/19/EU "Waste Electrical and Electronic Equipment".
Do not dispose of the product at public disposal sites. For environmentally friendly recycling
and the disposal of your old device contact a certified disposal company for electronic scrap
or your Siemens contact.
Keep to the local regulations.
You will find information on returning the product on the Internet pages of Siemens Industry
Online Support:
Link: (https://support.industry.siemens.com/cs/ww/en/view/109479891)

Preface
CP 343-1
8Manual, 12/2018, C79000−G8976−C201-08

CP 343-1
Manual, 12/2018, C79000−G8976−C201-08 9
Table of contents
Preface ................................................................................................................................................... 3
1 Properties / services.............................................................................................................................. 11
1.1 Application ..............................................................................................................................11
1.2 Enhanced functions ................................................................................................................11
1.3 Communication services.........................................................................................................12
1.4 Other services.........................................................................................................................14
1.5 The CP as Web server............................................................................................................15
2 Performance data ................................................................................................................................. 17
2.1 Transmission and reaction times ............................................................................................17
2.2 Number of possible Ethernet/PROFINET connections...........................................................17
2.3 Characteristics of S7 communication .....................................................................................18
2.4 Characteristic data of the SEND/RECEIVE Interface .............................................................19
2.5 PROFINET IO characteristic data...........................................................................................20
2.6 Characteristic data of the integrated switch............................................................................23
3 Requirements for use............................................................................................................................ 25
3.1 Operation in control device families........................................................................................25
3.2 Project engineering .................................................................................................................28
3.3 Programming ..........................................................................................................................29
4 LEDs..................................................................................................................................................... 31
5 Installation, connecting up and commissioning ...................................................................................... 35
5.1 Important notes on using the device.......................................................................................35
5.2 Installing the CP, connecting power and ground ....................................................................37
5.3 Connecting the CP to Ethernet ...............................................................................................40
6Configuration and operation .................................................................................................................. 43
6.1 Security recommendations .....................................................................................................43
6.2 Project engineering .................................................................................................................46
6.3 Controlling the mode...............................................................................................................46
6.4 Network settings .....................................................................................................................47
6.5 Influence of MPI on connections via Industrial Ethernet.........................................................49
6.6 PROFINET IO .........................................................................................................................49
6.6.1 How PROFINET IO devices start up in a large configuration.................................................49
6.6.2 PROFINET IO when operating other services at the same time ............................................49

Table of contents
CP 343-1
10 Manual, 12/2018, C79000−G8976−C201-08
6.6.3 Effects of multicast communication on RT communication ................................................... 50
6.7 IP configuration ...................................................................................................................... 50
6.7.1 Detection of double IP addressing in the network ................................................................. 50
6.7.2 Obtain IP address vie DHCP: CP STOP on expiry of the lease ............................................ 51
6.7.3 Configured S7 connections cannot be operated if the IP address is assigned over
DHCP ..................................................................................................................................... 51
6.7.4 IP access protection using the IP access control list with a PROFINET IO device............... 51
6.8 Media redundancy ................................................................................................................. 51
6.9 Timeofday synchronization .................................................................................................... 52
6.10 SNMP agent........................................................................................................................... 52
6.11 Possible security gaps on standard IT interfaces: preventing unauthorized access ............. 54
6.12 Programmed communication connections............................................................................. 55
6.12.1 Programmed communication connections with FB55 IP_CONFIG ....................................... 55
6.12.2 Programmed communications connections - assigning parameters to the ports .................. 55
6.12.3 IP access protection with programmed communication connections .................................... 55
6.13 Permitted length of ICMP packets ......................................................................................... 56
6.14 Downtime if an S7 connection aborts .................................................................................... 56
7 Service and maintenance...................................................................................................................... 57
7.1 Memory reset / reset to factory defaults ................................................................................ 57
7.2 Memory reset - ACL............................................................................................................... 58
7.3 Loading new firmware............................................................................................................ 58
7.4 Replacing a module ............................................................................................................... 59
7.4.1 Replacing older modules ....................................................................................................... 60
7.4.2 Module replacement / upgrading ........................................................................................... 60
7.4.3 Replacing a module without a programming device .............................................................. 62
8 Technical specifications ........................................................................................................................ 65
A Approvals ............................................................................................................................................. 67
B References ........................................................................................................................................... 71
Index .................................................................................................................................................... 77

CP 343-1
Manual, 12/2018, C79000−G8976−C201-08 11
Properties / services
1
1.1
Application
The CP 343-1 communications processor is intended for operation in a SIMATIC S7-300,
SIMATIC C7-300 automation system or SINUMERIK 840D power line. It allows the
connection of the S7-300 to Industrial Ethernet and supports PROFINET IO.
To integrate the CP in a linear bus or a ring, to connect a further Ethernet device or to use
PROFINET media redundancy, a 2-port ERTEC real-time switch with autocrossing,
autonegotiation and autosensing was integrated.
1.2
Enhanced functions
Abbreviations used with the CP 343-1 module
The module abbreviations used below for the CP 343-1 (for example EX30) correspond to
the last four characters of the mid section of the order number.
Requirement for configuring new functions of firmware version V3.0
To use the features listed below, the following STEP 7 version is necessary:
●STEP 7 V5.5 + Service Pack 2 + Hotfix 1 + HSP 1057
With STEP 7 Professional V11.0 SP2, only the functions of firmware version V2.2 of the CP
can be configured.
Functional enhancements of the EX30 from firmware version V2.6 to V3.0 - can be used with STEP 7
V5.5
The following new functions can be used with the module with firmware version 3.0:
●"Shared device" function as PROFINET IO device and as IO controller
●Use of PROFIenergy functionality
This requires the following PROFIenergy program blocks for the CP 343-1 in the
"SIMATIC_NET_CP" library with the STEP 7 version listed above:
–PE_Start_CP, PE_CMD_CP, PE_I_DEV_CP and the program block DS3_WRITE_CP
for the use of power modules of the ET 200S for PROFIenergy.
–The supplementary program blocks FC0 to FC8 for the PROFIenergy response data
can be found in the Standard Library.
You will find the documentation of the program blocks in the online help and in the
manual for the program blocks, see References, /10/ (Page 73).

Properties / services
1.3 Communication services
CP 343-1
12 Manual, 12/2018, C79000−G8976−C201-08
●New program block FB10 AG_CNTEX for connection diagnostics
●Configuration of the IO devices in the STEP 7 "I-device" dialog box (and as previously
using a GSDML file)
Functional enhancements of the EX30 with firmware version V3.0 - regardless of the configuration
tool used
●Advanced Web diagnostics (HTTP access) with the following additional options:
–Diagnostics of S7 connections
–Module identification
–Expansion of Web diagnostics for The "Shared device" function
●Update center of Web diagnostics with the following functions:
–Downloading firmware via the Web (HTTP access)
–Downloading of language files for diagnostics buffer texts in STEP 7 format for new
modules in the rack and for changing the language
●SNMP: Support of the MRP Monitoring MIB
Enhanced functions of earlier firmware versions and predecessor modules
You will find an overview of the earlier firmware versions and predecessor modules in the
version history of the Industrial Ethernet CPs on the Internet pages of Siemens Automation
Customer Support under the following entry ID:
56699406 (http://support.automation.siemens.com/WW/view/en/56699406)
You will find information about the characteristics of the individual firmware versions on the
Internet pages of Siemens Automation Customer Support under the following entry ID:
43409748 (http://support.automation.siemens.com/WW/view/en/43409748)
> Entry list > Entry type "Updates"
1.3
Communication services
The CP supports the following communication services:
●
PROFINET IO
PROFINET IO allows direct access to IO devices over Industrial Ethernet.
The CP can be used either as a PROFINET IO controller or as a PROFINET IO device,
but not both at the same time.
–PROFINET IO controller
IO controller mode with alarm block and acyclic data exchange by reading/writing a
data record.
–PROFINET IO device
Integration of the SIMATIC S7-300 automation system via the CP as an intelligent
PROFINET IO device (I-device).

Properties / services
1.3 Communication services
CP 343-1
Manual, 12/2018, C79000−G8976−C201-08 13
–Shared device
Individual submodules of the CP as IO device can be assigned up to two PROFINET
IO controllers in STEP 7 V5.5.
Note the information on configuring PROFINET IO systems with shared IO devices in
the "PROFINET System Description", see references, /13/ (Page 74).
●
S7 communication and PG/OP communication with the following functions:
–PG functions (including routing)
–Operator control and monitoring functions (HMI)
Multiplexing TD/OP connections
–Client and server for data exchange via communication blocks on S7 connections
configured at both ends.
Note
Blocks for S7
communication (see also STEP 7 online help or the "System Software
for S7
-300/400 System and Standard Functions" manual):
•
BSEND FB 12
•
BRCV FB 13
•
PUT FB 14
•
GET FB 15
•
USEND FB 8
•
URCV FB 9
•
C_CNTRL FC 62
–Server for data exchange on S7 connections configured at one end only without
communication blocks on the S7300 / C7300 station
●
Open communication services with the following functions:
–SEND/RECEIVE interface over ISO transport connections, ISOonTCP, TCP and UDP
connections
UDP frame buffering on the CP can be disabled during configuration. When
necessary, this allows you to achieve a shorter reaction time between the arrival of a
UDP frame and its evaluation on the CPU.
–Multicast over UDP connection
The multicast mode is made possible by selecting a suitable IP address when
configuring connections.
–FETCH/WRITE services (server; corresponding to S5 protocol) via ISO transport
connections, ISOonTCP connections and TCP connections;
The addressing mode can be configured for FETCH/WRITE access as S7 or S5
addressing mode.
–LOCK/UNLOCK with FETCH/WRITE services;
–Connection diagnostics from the user program

Properties / services
1.4 Other services
CP 343-1
14 Manual, 12/2018, C79000−G8976−C201-08
1.4
Other services
●
Media redundancy (MRP)
Within an Ethernet network with a ring topology, the CP supports the media redundancy
protocol MRP. You can assign the role of MRP client to the CP.
●
Time-of-day synchronization over Industrial Ethernet
Time-of-day synchronization can be configured in the following modes:
–SIMATIC mode
The CP receives MMS time messages and synchronizes its local time and the time of
the CPU.
Accuracy approx. +/- 1 second
You can choose whether or not the time of day is forwarded. The forwarding direction
can also be selected (station > LAN or LAN > station).
or
–NTP mode (NTP: Network Time Protocol)
The CP sends timeofday queries at regular intervals to an NTP server and
synchronizes its local time of day. The forwarding of the time-of-day to the CPU is
optional.
Accuracy approx. +/- 1 second
●
Addressing using a factoryset MAC address
The CP can be reached via the default or configured MAC address to allow an IP address
to be assigned.
●
SNMP agent
The CP supports data queries over SNMP in version V1 (Simple Network Management
Protocol). It delivers the content of certain MIB objects according to the MIB II standard,
LLDP MIB, Automation System MIB and MRP Monitoring MIB.
●
Module access protection
To protect the module from accidental or unauthorized access, protection can be
configured.
●
IP access protection (IPACL)
Communication via the CP of the local S7 station can be restricted to partners with
specific IP addresses.
●
IP configuration
For the PROFINET interface, you can configure how and with which method the CP is
assigned the IP address, the subnet mask and the address of a gateway.
As an alternative to STEP 7, you have the option of assigning the connection
configuration via a block interface in the user program (FB55: IP_CONFIG).
Configuration of S7 connections using FB55 is not possible.

Properties / services
1.5 The CP as Web server
CP 343-1
Manual, 12/2018, C79000−G8976−C201-08 15
●
Web diagnostics
With the aid of Web diagnostics, you can read out the diagnostics data from a station
connected via the CP to a PG/PC with a Web browser.
This makes it possible to read the diagnostics buffers of the intelligent modules in the
rack.
Using the integrated update center of the diagnostics pages, you can download new
firmware versions and diagnostics buffer message texts.
If you do not require the functions, you can disable it in the STEP 7 configuration and
disable port 80.
●
Connection diagnostics with the AG_CNTEX program block
With the AG_CNTEX program block, you can diagnose connections.
–When necessary, you can activate or deactivate connections or initiate
reestablishment of a connection.
–You can check the reachability of the connection partners using the ping function.
–You can find out which connection types are set up for the SEND / RECEIVE
interface.
1.5
The CP as Web server
Enabling the Web server function
To use the Web server functionality of the CP, enable the relevant option in STEP 7 in the
module properties, "Web" parameter group. This enables port 80 of the CP.
If you no longer require the functions, deactivate the function. The Web server function is
enabled as default.
Web diagnostics
The CP provides you with the functionality of a web server for access by means of a web
browser. The CP provides HTML pages for Web diagnostics. With the aid of Web
diagnostics, you can read out the diagnostics data from a station connected via the CP to a
PG/PC with an Internet browser.
With the following address, you have access to Web diagnostics:
http:\\<IP address of the CP>
Using the integrated update center of the diagnostics pages, you can download new
firmware versions and language files for the diagnostics buffer message texts.
For detailed information on Web diagnostics, refer to the general Part A of this manual, /1/
(Page 71).

Properties / services
1.5 The CP as Web server
CP 343-1
16 Manual, 12/2018, C79000−G8976−C201-08
Diagnostics buffer entries
When supplied, diagnostics buffer entries shown on diagnostics pages are always in English.
This is the case whichever language you have selected to display the Web pages.
How to download other language files to the CP and further information about Web
diagnostics can be found in the general Part A of this manual.
Web browser
To access the HTML pages on the CP, you require a Web browser. The following Web
browsers are suitable for communication with the CP (other browsers also possible):
●Internet Explorer (recommended version: as of 7.0)
●Chrome (recommended version: as of 12.0)
●Opera (recommended version: as of 9.2)
●Firefox (recommended version: as of 4.0)
You will find these Web browsers, information and any necessary addons on the Internet.

CP 343-1
Manual, 12/2018, C79000−G8976−C201-08 17
Performance data
2
2.1
Transmission and reaction times
Measured values on the Internet
Note
Measured values of transmission and reaction times over Ethernet, PROFIBUS and
PROFINET networks for a series of configurations can be found on the Internet at
the
following address:
http://www.siemens.com/automation/pd (
http://www.siemens.com/automation/pd)
2.2
Number of possible Ethernet/PROFINET connections
Maximum number of parallel connections
Table 2- 1 Maximum number of parallel connections
Characteristic
Explanation / values
Permitted number of simultaneous connections in
total over Industrial Ethernet
32 maximum
Example of maximum load
You can, for example, operate:
●16 S7 connections, of which
–8 PUT jobs
–8 GET jobs
●16 SEND/RECV connections, of which
–2 ISO-on-TCP connections
–8 TCP connections
–6 UDP connections

Performance data
2.3 Characteristics of S7 communication
CP 343-1
18 Manual, 12/2018, C79000−G8976−C201-08
Also:
●Further TCP connections for Web diagnostics
●PROFINET IO
–As PROFINET IO device:
1 PROFINET connection to a PROFINET IO controller
or
–As shared device:
2 PROFINET connections to 2 PROFINET IO controllers
or
–As PROFINET IO controller:
Max. 32 PROFINET connections to PROFINET IO devices
2.3
Characteristics of S7 communication
Number of connections
Table 2- 2 Number of connections for S7 communication
Characteristic
Explanation / values
Number of connections for S7 communication via
Industrial Ethernet.
in each case, up to
•16 operator control and monitoring functions (HMI)
•16 S7 connections configured at one end
•16 S7 connections configured at both ends
The number depends on the CPU type being used; the valid values
can be found in /1/ (Page 71).
You should still keep to the maximum number of Ethernet connec-
tions specified in the section Number of possible Ethernet/PROFINET
connections (Page 17).
maximum 16 resources
For each executed S7 communications function, a job resource is
required. If the CP has 16 job resources, then only 1 PUT or GET job
can be executed at one time on each of the 16 S7 connections. The
same applies to BSEND/BRECV and USEND/URECV jobs.
LAN interface - data field length generated by CP
per protocol data unit
•sending
•receiving
•240 bytes / PDU
•240 bytes / PDU

Performance data
2.4 Characteristic data of the SEND/RECEIVE Interface
CP 343-1
Manual, 12/2018, C79000−G8976−C201-08 19
Data lengths of the S7 services
Table 2- 3 Possible data lengths of the S7 services
S7 service
Maximum block length per frame
PUT / GET
160 bytes
USEND/URCV 160 bytes
BSEND/BRCV
32 kB
Execution times for FBs for S7 connections
The execution time required to process the function blocks (FBs PUT, GET, USEND, URCV,
BSEND, BRCV) required on the S7-300 / C7-300 CPU is decisive for the calculation of the
CPU cycle times (OB1) for S7 connections.
Note
Measurements of transmission and reaction times in Ethernet, PROFIBUS and PROFINET
networks for a series of configurations can be found on
the Internet at the following address:
25209605 (
http://support.automation.siemens.com/WW/view/en/25209605)
2.4
Characteristic data of the SEND/RECEIVE Interface
The SEND/RECEIVE interface provides access to communication over TCP, ISOonTCP,
ISO transport and UDP connections.
The following characteristics are important:
Table 2- 4 Characteristic data of the SEND/RECEIVE interface
Characteristic
Explanation / values
Number of ISO transport connections, ISO-on-
TCP connections + TCP connections + UDP
connections in total
16 maximum
Notes:
•All UDP connections are also possible in
multicast mode.
•Free UDP connections are supported by the
CP.
Maximum data length for the blocks AG_SEND
(as of V4.0) and AG_RECV (as of V4.0)
AG_SEND and AG_RECV allow the transfer of
blocks of data with the following lengths:
•1 to 8192 bytes for ISO transport, ISO-on-
TCP, TCP
•1 to 2048 bytes for UDP
Restrictions for UDP

Performance data
2.5 PROFINET IO characteristic data
CP 343-1
20 Manual, 12/2018, C79000−G8976−C201-08
Characteristic
Explanation / values
•Transfer is not confirmed The transfer of UDP frames is unconfirmed, in
other words the loss of messages is not detected
or displayed by the send block (AG_SEND).
•No receipt of UDP broadcast To avoid communications overload of the CP due
to high broadcast load, the CP does not allow
receipt of UDP broadcasts.
•UDP frame buffering Size of the frame buffer with buffering enabled: 2
Kbytes
Note:
Following a buffer overflow, newly arriving frames
are discarded.
Execution times of the FCs AG_SEND / AG_RECV
The execution time required to process the FC blocks (AG_SEND, AG_RECV) required on
the S7-300 / C7-300 CPU is decisive for the calculation of the CPU cycle times (OB1) for
SEND/RECEIVE connections.
Note
Measurements of transmission and reaction times i
n Ethernet, PROFIBUS and PROFINET
networks for a series of configurations can be found on the Internet at the following address:
25209605 (
http://support.automation.siemens.com/WW/view/en/25209605)
2.5
PROFINET IO characteristic data
Possible modes with PROFINET IO
In PROFINET IO, the CP can operate as a PROFINET IO device or as a PROFINET IO
controller.
Configuration limits of the CP as a PROFINET IO controller
The CP supports the following maximum configuration as a PROFINET IO controller:
Table 2- 5 Configuration limits of the CP as a PROFINET IO controller
Characteristic
Explanation / values
Number of operable PROFINET IO devices
32 *), **)
Size of the input area over all PROFINET IO devices ***)
1024 bytes max.
Size of the output area over all PROFINET IO devices 1024 bytes max.
Size of the IO data area per submodule of a module in an IO
device