Siemens SIMATIC NET CP 243-1 User manual

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SIMATIC NET
S7-200 - Industrial Ethernet
CP 243-1
Operating Instructions
03/2012
C79000-G8976-C244-02
Preface
Application and properties
1
Installation and
commissioning
2
Configuration
3
Programming
4
Diagnostics
5
Technical specifications
6
Certification
7
Access from and to the S7-
200
A
Timeouts
B
Sample program
C
Training, Service & Support
D

Legal information
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
with a safety alert symbol, indicates that minor personal injury can result if proper precautions are not taken.
CAUTION
without a safety alert symbol, indicates that property damage can result if proper precautions are not taken.
NOTICE
indicates that an unintended result or situation can occur if the relevant information is not taken into account.
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.
Siemens AG
Industry Sector
Postfach 48 48
90026 NÜRNBERG
GERMANY
Order number: C79000-G8976-C244
Ⓟ 04/2012 Technical data subject to change
Copyright © Siemens AG 2004, -,
2012.
All rights reserved

CP 243-1
Operating Instructions, 03/2012, C79000-G8976-C244-02 3
Preface
Validity of this manual
This document contains information on the following product:
CP 243-1
Order number: 6GK7243-1EX01-0XE0
Hardware product version 1
Firmware version V1.0
The device is a communications processor of the SIMATIC S7-200 for Industrial Ethernet
and information technology.
You will also find the current version of the manual on the Internet pages of Siemens
Automation Customer Support under the following entry ID:
42122427 (http://support.automation.siemens.com/WW/view/en/42122427)
Purpose of the manual
This manual supports when using the CP 243-1 communications processor. It provides you
with information on how to communicate with this communications processor via Industrial
Ethernet and how to use the Information Technology (IT) functions.
New in this issue
Revision of the manual.
Replaced documentation
This manual replaces the manual release 01/2010.
Requirements
To be able to understand how the CP 243-1 works, you should be familiar with this manual
and the "SIMATIC S7-200 Automation System" system manual and have programming
experience in STEP 7-Micro/WIN.
You will find the system manual on the Internet under the following entry ID: 1109582
(http://support.automation.siemens.com/WW/view/en/1109582)
You also require a basic understanding of TCP/IP, FTP, e-mail, HTML, Web browsers and
Java.

Preface
CP 243-1
4 Operating Instructions, 03/2012, C79000-G8976-C244-02
Target group
This manual is intended for engineers, programmers, commissioning personnel and
maintenance personnel with a general knowledge of automation and communications
systems as well as operator control and monitoring systems.
Sample program
This manual contains a sample program that will help you to program the CP 243-1. This
sample program can be run on an S7-200 CPU, type 224. If you want to run this sample
program on another S7-200 CPU, you may need to adjust the configuration for the sample
program.
Address label: MAC address
The CP 243-1 ships with a fixed MAC address. You will find the MAC address beneath the
top cover of the device.
SIMATIC NET glossary
Explanations of the specialist terms used in this documentation can be found in the SIMATIC
NET glossary.
You will find the SIMATIC NET glossary here:
● SIMATIC NET Manual Collection
The DVD ships with certain SIMATIC NET products.
● On the Internet under the following entry ID:
50305045 (http://support.automation.siemens.com/WW/view/en/50305045)

Preface
CP 243-1
Operating Instructions, 03/2012, C79000-G8976-C244-02 5
Security messages
NOTICE
For its automation and drives product portfolio, Siemens provides IT security mechanisms
to support secure operation of the plant/machine. Our products are continuously being
further developed also taking into account the aspect of IT security. We therefore
recommend that you regularly check for updates of our products and that you only use the
latest versions. You will find information in:
(http://support.automation.siemens.com/WW/llisapi.dll?func=cslib.csinfo2&aktprim=99&lang
=en)
Here, you can register for a product-specific newsletter.
For the secure operation of a plant/machine, it is also necessary to integrate the automation
components in a full IT security concept for the entire plant/machine that represents the
state of the art in IT technology. You will find information on this in:
(http://www.siemens.com/industrialsecurity)
Products from other manufacturers that are being used must also be taken into account.

Preface
CP 243-1
6 Operating Instructions, 03/2012, C79000-G8976-C244-02

CP 243-1
Operating Instructions, 03/2012, C79000-G8976-C244-02 7
Table of contents
Preface ...................................................................................................................................................... 3
1 Application and properties ....................................................................................................................... 11
1.1 Using the CP................................................................................................................................11
1.2 Compatibility with predecessor models .......................................................................................11
1.3 Compatibility with S7-200 CPUs..................................................................................................11
1.4 Overview of the functions.............................................................................................................13
1.5 S7 communication via Industrial Ethernet ...................................................................................15
1.5.1 Preliminary overview....................................................................................................................15
1.5.2 Types of communication..............................................................................................................15
1.5.3 Communications partners ............................................................................................................16
1.6 IT communication.........................................................................................................................19
1.6.1 Preliminary overview....................................................................................................................19
1.6.2 Types of communication..............................................................................................................20
1.6.3 E-mails .........................................................................................................................................20
1.6.4 FTP server ...................................................................................................................................23
1.6.5 FTP client.....................................................................................................................................25
1.6.6 HTTP server.................................................................................................................................28
1.7 Configuration and programming ..................................................................................................32
1.8 File system...................................................................................................................................33
1.9 User administration ......................................................................................................................34
1.10 Safety ...........................................................................................................................................36
1.10.1 Storing the configuration data......................................................................................................36
1.10.2 Data security ................................................................................................................................37
1.10.3 Reliability of communication ........................................................................................................38
1.11 Connectors...................................................................................................................................39
1.12 Codes: Front LEDs ......................................................................................................................40
2 Installation and commissioning................................................................................................................ 43
2.1 Important notes on installation and commissioning.....................................................................43
2.2 Installation and electrical connections .........................................................................................45
2.3 Dimensions for installation in a switching panel ..........................................................................48
2.4 Dimensions for installation on a DIN rail......................................................................................48
2.5 Installation in a panel ...................................................................................................................49
2.6 Installation on a standard DIN rail................................................................................................50
2.7 Replacing a module .....................................................................................................................51
2.8 Uninstalling the CP 243-1 ............................................................................................................51

Table of contents
CP 243-1
8 Operating Instructions, 03/2012, C79000-G8976-C244-02
3 Configuration ........................................................................................................................................... 53
3.1 Configuration options .................................................................................................................. 53
3.2 Value ranges of the configuration data ....................................................................................... 54
3.2.1 IP addresses ............................................................................................................................... 54
3.2.2 Subnet mask ............................................................................................................................... 54
3.2.3 TSAPs ......................................................................................................................................... 55
3.2.4 Ports............................................................................................................................................ 55
3.2.5 E-mail tags .................................................................................................................................. 55
3.3 Configuring a CP 243-1 with STEP 7.......................................................................................... 57
3.3.1 Basic configuration...................................................................................................................... 58
3.3.2 Configuration of user administration ........................................................................................... 61
3.3.3 Configuration of the e-mail functions .......................................................................................... 62
3.3.4 Configuring the FTP functions .................................................................................................... 64
3.3.5 Completing configuration ............................................................................................................ 65
3.4 Other options when configuring a CP 243-1............................................................................... 65
3.4.1 Occupied special memory (SM area).......................................................................................... 66
3.4.2 Structure of the configuration data block (CDB) ......................................................................... 67
3.4.3 Structure of the network parameter block (NPB) ........................................................................ 72
3.4.4 Structure of the network data block (NDB) ................................................................................. 72
3.4.5 Structure of the Internet data block (IDB) ................................................................................... 75
3.4.6 Structure of the configuration file for user administration (.udb file) ........................................... 76
3.4.7 Structure of the configuration file for the e-mail client (.edb file)................................................. 79
3.4.8 Structure of the configuration file for the e-mail client (.adb file)................................................. 82
3.4.9 Structure of the configuration file for the FTP client (.fdb file)..................................................... 84
3.5 Configuration of a communications partner with STEP 7 ........................................................... 88
3.6 Reaction of the CP 243-1 to configuration errors ....................................................................... 91
4 Programming ........................................................................................................................................... 93
4.1 ETHx_CTRL ................................................................................................................................ 94
4.2 ETHx_CFG.................................................................................................................................. 96
4.3 ETHx_XFR .................................................................................................................................. 97
4.4 ETHx_EMAIL............................................................................................................................... 99
4.5 ETHx_FTPC .............................................................................................................................. 101
5 Diagnostics ............................................................................................................................................ 105
5.1 Diagnostic options..................................................................................................................... 105
5.2 Error messages of the CP 243-1 .............................................................................................. 108
5.2.1 Error messages in byte format.................................................................................................. 110
5.2.2 Error messages in word format................................................................................................. 114
5.2.3 Error messages of the test mechanism for e-mails .................................................................. 117
6 Technical specifications......................................................................................................................... 119
7 Certification............................................................................................................................................ 121

Table of contents
CP 243-1
Operating Instructions, 03/2012, C79000-G8976-C244-02 9
A Access from and to the S7-200.............................................................................................................. 125
A.1 Access from S7-300/400 to S7-200...........................................................................................125
A.2 Access by CP 243-1 to S7-200/300/400....................................................................................126
B Timeouts................................................................................................................................................ 129
C Sample program .................................................................................................................................... 131
D Training, Service & Support................................................................................................................... 139
Index...................................................................................................................................................... 141

Table of contents
CP 243-1
10 Operating Instructions, 03/2012, C79000-G8976-C244-02

CP 243-1
Operating Instructions, 03/2012, C79000-G8976-C244-02 11
Application and properties 1
1.1 Using the CP
Application
The CP 243-1 is a communications processor intended for operation in an S7-200
automation system. It allows the connection of the S7-200 to Industrial Ethernet (IE). The
use of the CP 243-1 means that communication via Ethernet is also possible at the lower
performance end of the S7 product family.
As a result, an S7-200 can be configured, programmed and diagnosed even at a distance
using STEP 7 Micro/WIN 32 via Ethernet. Using a CP 243-1 also means that an S7-200 can
communicate with another S7-200, an S7-300 or S7-400 controller via Ethernet.
Communication with an OPC server is also possible.
The IT functions of the CP 243-1 form the basis for monitoring and, if necessary, also
manipulating automation systems with a Web browser from a networked PC. In addition,
diagnostics messages can also be e-mailed from a system. Using the IT functions, it is very
easy to exchange entire files with other computer and controller systems.
Industrial Ethernet is the network for the process control level and the cell level of the
SIMATIC NET open communication system. Physically, Industrial Ethernet is an electrical
network based on shielded, coaxial lines, twisted pair cabling, and an optical network of
fiber-optic conductors. Industrial Ethernet is defined by the international standard IEEE
802.3.
1.2 Compatibility with predecessor models
Predecessor models
The CP 243-1 (6GK7243-1EX01-0XE0) described here is the successor to the predecessor
models CP 243-1 (6GK7243-1EX00-0XE0) and CP 243-1 IT (6GK7243-1GX00-0XE0) and is
fully compatible with them.
1.3 Compatibility with S7-200 CPUs
The CP is compatible with the following CPUs and firmware versions of the CPU:

Application and properties
1.3 Compatibility with S7-200 CPUs
CP 243-1
12 Operating Instructions, 03/2012, C79000-G8976-C244-02
•CPU 222 CPU firmware version 1.2 or higher
•CPU 224 CPU firmware version 1.2 or higher
•CPU 226 CPU firmware version 1.2 or higher
•CPU 226XM CPU firmware version 1.2 or higher
A maximum of 2 expansion modules can be installed on the CPU 222.
Up to 7 expansion modules can be connected to CPUs 224, 226 and 226XM.
You will find information on the compatibility of the data type when accessing the
S7-200/300/400 in the appendix Access from and to the S7-200 (Page 125).
NOTICE
Only one CP 243-1 may be connected to an S7-200 CPU. If additional CP 243-1
communications processors are connected, the S7-200 system may not function correctly.

Application and properties
1.4 Overview of the functions
CP 243-1
Operating Instructions, 03/2012, C79000-G8976-C244-02 13
1.4 Overview of the functions
The CP 243-1 provides the following functions:
● S7 communication
– High-speed data communication via Industrial Ethernet. Communication is based on
standard TCP/IP
– Ethernet access via RJ-45 jack
– Simple connection to an S7-200 system via the S7-200 bus
– Permits a flexible and distributed automation structure
– Basis for simple further processing and archiving of process data
– Permits simultaneous communication with up to 8 S7 controllers
– Provides a link to S7-OPC
– Simple network administration
– S7 communication services "XPUT/XGET" as client and server
– S7 communication services "READ/WRITE" as server
– A keepalive time can be configured for all TCP transport connections with active and
passive partners
● IT communication
– File system for permanent storage of Web and configuration files on the CP 243-1
– SMTP client for sending e-mails. In addition to pure text information, embedded
variables can also be transferred. The current value of such a variable obtained only
when the e-mail is sent.
– Configuration of up to 32 e-mails with up to 1024 characters each
– FTP server for access to the file system of the CP 243-1
– FTP client for exchanging data with an FTP server
– Configuration of up to 32 FTP client operations
– The FTP client function supports the READ, WRITE and DELETE commands.
– Access by the FTP client to the FTP server of the CP 243-1
– HTTP server for read and write access to process and status data of the S7-200
system via up to four Web browsers at one time
– Ready-made HTML pages for diagnostics of the S7-200 system and for access to
process variables
– Sending a test e-mail via a ready-made HTML page
– Storage of your own HTML pages and Java applets in the file system of the CP 243-1
– Availability of Java applets and beans for development of user-defined HTML pages
and Java applets

Application and properties
1.4 Overview of the functions
CP 243-1
14 Operating Instructions, 03/2012, C79000-G8976-C244-02
– User administration for up to 8 users with user-specific privileges for access to files,
status information and process variables
● Configuration:
– Remote programming, configuration and diagnostics of an S7-200 system (for
example program upload and download or status indications) via Industrial Ethernet
and STEP 7 Micro/WIN 32.
– Module replacement possible without having to program/configure the Ethernet
functions again (Plug & Play). Since the configuration of the IT functions is stored on
the CP 243-1, this must be downloaded to the module again when the CP 243-1 is
replaced.
● Watchdog timer
The CP 243-1 is equipped with a watchdog function. The watchdog starts each time the
CP 243-1 starts up. If the watchdog monitoring is triggered, the CP 243-1 is automatically
reset. This restarts the CP 243-1. During this time, the CP 243-1 reports a parity error to
the S7-200 CPU. Handling such an error is described in the documentation of STEP 7
Micro/WIN 32.
● Can be addressed using preset MAC address (48-bit value)
The MAC address is set for each CP 243-1 in the factory. The MAC address can be
found under the upper front panel. An IP address can be assigned to the CP 243-1 using
BOOTP/DHCP and the preset MAC address.
Note
The Telnet protocol is implemented on this device. This is used only for manufacturing
purposes and is not released for productive applications.
Communications standards
The software of the CP 243-1 is compatible with the following standards:
● S7 XPUT/XGET and S7 READ/WRITE
● S7-200 I/O bus specification
● HTTP 1.0 to RFC 1945
● FTP to RFC 959
● SMTP to RFC 2821/2822 (only functions for sending e-mails)
The position in an S7-200 system at which a CP 243-1 can be operated depends on the
firmware version of the S7-200 CPU, see also section Installation and electrical connections
(Page 45).

Application and properties
1.5 S7 communication via Industrial Ethernet
CP 243-1
Operating Instructions, 03/2012, C79000-G8976-C244-02 15
1.5 S7 communication via Industrial Ethernet
1.5.1 Preliminary overview
S7 communication via Industrial Ethernet permits program-controlled communication using
communication SFBs/FBs and configured S7 connections. The CP 243-1 supports S7
communication via Industrial Ethernet with the XPUT/XGET and READ/WRITE services. Up
to 212 bytes of user data can generally be transmitted per request. If the CP 243-1 is
operating as a server, up to 212/222 bytes of user data can be transferred in read requests
(see Technical specifications (Page 119)).
The CP 243-1 supports a maximum of 8 S7 communications channels to clients or servers
on one or more remote communications partner. The CP 243-1 works according to the
client/server principle on each channel. Per channel only one request at a time is accepted,
processed and answered with a positive or negative response. The CP 243-1 only accepts a
new request after a response has been sent.
If the CP 243-1 receives several requests on a channel configured as a server, only the first
request is processed. The subsequent requests are ignored until completion of the
transaction, in other words, until a response is sent. The CP 243-1 has no channel-specific
request administration and does not buffer requests.
Requirements for communication with a PC/PG
Just as previously, a PG/PC can access the S7-200 CPU via the PPI interface. This access
is also possible via Ethernet using a CP 243-1. The following requirements must first be met:
● An Ethernet card is installed and configured on the PG/PC and an Ethernet and TCP/IP
connection to the CP 243-1 exists (where necessary via routers, firewalls, etc.)
● STEP 7 Micro/WIN 32, version 3.2.3 or higher, is installed on the PG/PC.
● The CP 243-1 has a valid IP address. This address may be permanently specified in the
configuration or obtained from a BOOTP/DHCP server.
At any one time, only one STEP 7 Micro/WIN 32 can communicate via a CP 243-1 with the
S7-200 CPU. The Ethernet interface must be used when configuring the IT services.
1.5.2 Types of communication
The CP 243-1 has three types of S7 communication relationships that can be used
individually or as a combination.
1. Link to STEP 7-Micro/WIN 32
2. Link to other remote components of the SIMATIC S7 family
3. Link to OPC-based applications on a PC/PG

Application and properties
1.5 S7 communication via Industrial Ethernet
CP 243-1
16 Operating Instructions, 03/2012, C79000-G8976-C244-02
1.5.3 Communications partners
Communications partners
● S7-200 CPU with CP 243-1
● S7-300 CPU with CP 343-1, CP 343-1 Lean, CP 343-1 IT / Advanced
● S7-400 CPU with CP 443-1, CP 443-1 IT / Advanced
● PG/PC with OPC server
● PG/PC with STEP 7 Micro/WIN 32
The STEP 7 HW Config program shows you the types of S7-300 CPUs and S7-400 CPUs
that support the S7 protocol XPUT/XGET and can therefore communicate with the CP 243-1.
When you select an S7-300 or S7-400 CPU in the catalog of HW Config, this CPU must
support the "S7 communication" function.
Remember that the CP 243-1 does not support pure ISO connections. You should therefore
check the supported protocols of the communications partner of the CP 243-1.
NOTICE
Only one CP 243-1 may be connected to an S7-200 CPU. If additional CP 243-1
communications processors are connected, the S7-200 system may not function correctly.
Note
If you require communication with an OPC server, remember that the CP 243-1 does not
support automatic querying of the objects on the S7-200 (for example DBxx etc.).
A CP 243-1 can only communicate with an OPC server if this server supports the two S7
services READ and WRITE.

Application and properties
1.5 S7 communication via Industrial Ethernet
CP 243-1
Operating Instructions, 03/2012, C79000-G8976-C244-02 17
Micro/WIN
CPU 22x
CP 243-1
...
CPU 3xx
CP 343-1 IT
......
CPU 4xx
CP 443-1 IT
......
OPC server
OPC client
S7-200 S7-300 S7-400 PC
PC
Ethernet
XPUT / XGET re ad / w rite
max. 8 x
1 x
CPU 22x
CP 243-1
...
S7-200
BOOTP /
DHCP server
PC
Figure 1-1 Communications partners
A CPU 22x with a CP 243-1 can communicate both with other S7-200, S7-300 and S7-400
systems and with an OPC server.
A maximum of 8 connections are possible in addition to a STEP 7 Micro/WIN connection.
Configuring and programming connections for S7 stations
To configure communication between an S7-200 and an S7-300, S7-400 or an OPC server,
you will need both STEP 7 Micro/WIN 32, version 3.2.3 or higher, and STEP 7, version 5.1
with service pack 3 or higher (with NCM for Industrial Ethernet).
The S7-200 station is configured and programmed with STEP 7 Micro/WIN 32. You will need
STEP 7 with NCM for Industrial Ethernet to configure and program the S7-300 or S7-400 or
the OPC server.
Data exchange via Industrial Ethernet
10 and 100 Mbps networks are supported in full and half duplex. The CP 243-1 also
supports the autonegotiation function for automatically negotiating the operating mode and
the transmission speed to be used. The mode and the transmission speed can also be
permanently specified by the user when configuring the CP 243-1. If the CP 243-1 does not
have a valid configuration, it uses "autonegotiation" mode as default.

Application and properties
1.5 S7 communication via Industrial Ethernet
CP 243-1
18 Operating Instructions, 03/2012, C79000-G8976-C244-02
Note
Autonegotiation mode only works when all connected network components support this
mode.
Industrial Ethernet and TCP/IP do not allow time-deterministic data flows. There is no way to
know when a remote CPU will execute the requests. The responses of the remote CPU are
asynchronous to the CPU cycle of the local S7-200 CPU. This is why TCP/IP-based
communication is not ideally suitable for use in distributed applications with strict time
requirements (for example control circuits, cyclic precisely timed sampling).
S7 communication
The XPUT and XGET S7 services are used to exchange data between two controllers. The
CP 243-1 can be used both as client and as server.
Communication between a CP 243-1 and an OPC server running on a PC/PG is based on
the READ and WRITE S7 services. In this case, the CP 243-1 always functions as the
server. Other S7 services, for example the service for automatic querying of objects currently
on an S7-200 (DBs, ...) are not supported here.
The following data types or data areas are supported by the CP 243-1:
● CP 243-1 as client
Read and write access:
– Data type is always BYTE
– Only variables can be accessed on the local system.
– Accessible memory areas on the partner system are inputs, outputs, bit memory and
variables when an S7-200 is the partner.
– Accessible memory areas on the partner system are inputs, outputs, bit memory and
data areas when an S7-300 or an S7-400 is the partner.
● CP 243-1 as server
Write access:
– Data type is BOOL, BYTE, WORD or DWORD
– The use of the data types CHAR, INT, DINT and REAL depends on the firmware
version of the S7-200 CPU being used.
– Accessible memory areas on the local system are inputs, outputs, variables, bit
memory and status bits.
Read access:

Application and properties
1.6 IT communication
CP 243-1
Operating Instructions, 03/2012, C79000-G8976-C244-02 19
– Data type is BOOL, BYTE, WORD or DWORD
– The use of the data types CHAR, INT, DINT and REAL depends on the firmware
version of the S7-200 CPU being used.
– Accessible memory areas on the local system are inputs, outputs, variables, bit
memory, system area and status bits.
Note
When an S7-300 or S7-400 is acting as the server for a client running on an S7-200
system, the CP 243-1 expects that this server will always have a passive role. This
means that, the S7-300 or S7-400 system is not allowed to send S7 requests to the
S7-200 system.
Communication with STEP 7 Micro/WIN 32
With communication between a CP 243-1 and STEP 7 Micro/WIN 32, the CP 243-1 is
always the server. STEP 7 Micro/WIN 32 always acts as the client.
S7 bus communication
All access to all data areas of the S7-200 CPU is always possible. Read and write access
does not depend on the CPU mode (RUN, TERM or STOP).
1.6 IT communication
1.6.1 Preliminary overview
Preliminary overview
The CP 243-1 supports not only S7 communication via Industrial Ethernet but also a series
of IT functions at the same time. These include data exchange via FTP, sending e-mails, and
the option of permitting up to four Web browsers to access data and status information
simultaneously on the S7-200 system.
Sending an e-mail or active file access using FTP is initiated by the S7-200 user program.
Only one request can be active for each of these two functions at any one time. The user
program cannot start another request until the CP 243-1 has positively or negatively
acknowledged the currently active request.

Application and properties
1.6 IT communication
CP 243-1
20 Operating Instructions, 03/2012, C79000-G8976-C244-02
Ethernet
HTTP
CPU 2xx
CP 243-1
...
S7-200
...
HTTP
bro w ser
4x
FTP
serve r
FTP
clie n t
E-mail
serve r
E-mail
serve r
FTP
FTP
SMTP
Figure 1-2 Overview of the IT functions
1.6.2 Types of communication
In addition to the S7 communication relations described in chapter Types of communication
(Page 15), the CP 243-1 allows four types of IT communication relations that can be used
individually or as a combination.
1. Communication with an e-mail server
2. Communication with an FTP client located on a remote system.
3. Communication with an FTP server. Such a server is typically located on a remote
system. A link to the FTP server running on the CP 243-1 of the local S7-200 system is
also possible.
4. Communication with up to four Web browsers running on remote systems
1.6.3 E-mails
How it works
The SMTP protocol controls the transfer of e-mails. An e-mail consists of one or two address
fields, a subject field and a field for the actual text message.