Siemens SIMATIC ET 200AL System Manual page 693

Table of contents
Preface ................................................................................................................................................... 3
1 Documentation guide ............................................................................................................................ 10
2 Product overview .................................................................................................................................. 15
3 Communications services ..................................................................................................................... 20
3.1 Overview of communication options ....................................................................................... 20
3.2 Communications protocols and port numbers used for Ethernet communication .................. 23
3.3 Overview of connection resources .......................................................................................... 28
3.4 Setting up a connection .......................................................................................................... 29
3.5 Data consistency ..................................................................................................................... 33
3.6 Secure Communication........................................................................................................... 36
3.6.1 Basics of Secure Communication ........................................................................................... 36
3.6.2 Confidentiality through encryption .......................................................................................... 39
3.6.3 Authenticity and integrity through signatures .......................................................................... 41
3.6.4 Managing certificates with STEP 7 ......................................................................................... 45
3.6.5 Examples for the management of certificates. ....................................................................... 49
3.6.6 Example: HTTP over TLS ....................................................................................................... 54
3.7 SNMP ...................................................................................................................................... 58
3.7.1 Disabling SNMP ...................................................................................................................... 58
3.7.2 Example: Disabling SNMP for a CPU 1516-3 PN/DP ............................................................ 59
4 PG communication ................................................................................................................................ 61
5 HMI communication .............................................................................................................................. 64
6 Open User Communication ................................................................................................................... 66
6.1 Overview of Open User Communication ................................................................................ 66
6.2 Protocols for Open User Communication ............................................................................... 67
6.3 Instructions for Open User Communication ............................................................................ 69
6.4 Open User Communication with addressing via domain names ............................................ 73
6.5 Setting up Open User Communication via TCP, ISO-on-TCP, UDP and ISO ....................... 76
6.6 Setting up communication over FDL ....................................................................................... 82
6.7 Setting up communication with Modbus TCP ......................................................................... 85
6.8 Setting up communication via e-mail ...................................................................................... 88
6.9 Setting up communication via FTP ......................................................................................... 89
Communication
Function Manual, 12/2017, A5E03735815-AF
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