Entry type: FAQ, Entry ID: 38051505, Entry date: 09/12/2014
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With which devices can the S7-1200 communicate over the integrated PROFINET interface and which protocols does the S7-1200 support?

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Communication partners of S7-1200
The S7-1200 CPU communicates with the devices below over the integrated PROFINET interface:

  • Other S7 CPUs (S7-200, S7-300, S7-400, S7-1200, S7-1500)
  • Programming devices
  • HMI devices (SIMATIC Basic Panels and SIMATIC Comfort Panels, for example)
  • Devices that support Open User Communications

Maximum number of simultaneous, asynchronous communication connections
The S7-1200 CPU supports the following maximum number of simultaneous, asynchronous communication connections:
 

Connection type Description and maximum number of connections
Open User Communications The S7-1200 CPU supports 8 connections for Open User Communications (active or passive) using the following instructions: T_SEND_C, T_RECV_C, TCON, TDISCON, TSEND and TRECV.

Note
Modbus TCP uses Open User Communications (OUC) connections as Modbus communications path. There can be multiple client-server connections in addition to the connection between STEP 7 and the CPU. Mixed client and server connections are supported up to the maximum number permitted to be supported by the CPU for Open User Communications.

S7 communication
  • 3 connections for a passive S7-1200 CPU communicating with an active S7 CPU or LOGO!, this means the S7-1200 is S7 server. The active S7 CPU or LOGO! establishes the connection and uses PUT and GET instructions (S7-300, S7-400, S7-1200 and S7-1500) or the ETHx_XFER instruction (S7-200)
    to read and write data.
  • 8 connections for an active S7-1200 CPU or LOGO! communicating with a passive S7 CPU, this means the S7-1200 is S7 client. The active S7-1200 CPU establishes the connection and uses PUT and GET instructions to read and write data.
HMI connections Firmware V2 and V3
The S7-1200 CPU provides dedicated HMI connections to support up to 3 HMI devices.

Firmware V4
From Frimware V4 you can configure the number of HMI connections required for your application through the TIA Portal.

PG connections  The S7-1200 CPU provides connections to support 1 programming device (PG).
Web server connections (HTTP) The S7-1200 provides connections for the web server.


Fig. 01

PROFINET and PROFIBUS

  • S7-1200 CPU with firmware version V2.02 to V2.2
    For PROFINET, the S7-1200 CPU supports a maximum of 8 PROFINET IO devices and 128 submodules, whichever of the two is reached first. PROFIBUS supports a maximum of 16 DP slaves on one DP master with a maximum of 256 submodules per DP slave.
    A maximum of 16 DP slaves and IO devices altogether is supported.
  • S7-1200 CPU with firmware version V3.0 or higher
    As from firmware version V3.0 the S7-1200 CPU supports 16 PROFINET IO devices with a maximum of 256 submodules. PROFIBUS supports 32 DP slaves with a maximum of 512 submodules per DP slave.

Integrated PROFINET interface of the S7-1200
The integrated PROFINET interface of the S7-1200 CPU is implemented as RJ45 socket.


Fig. 02

Supported protocols
The S7-1200 supports the following protocols over the integrated PROFINET interface:
 

Protocol Firmware version
TCP V1.0
ISO-on-TCP (RFC 1006) V1.0
UDP V2.0
PROFINET RT - Basic Services and IO Controller V2.0
PROFINET IO device V4.0
S7 communication (S7 server) V1.0
S7 communication the PUT/GET instructions (S7 client) V2.0
Web server  V2.0
Modbus TCP V2.1
HTTP (Hypertext Transfer Protocol) V2.0
HTTPS - Hyper Text Transfer Protocol Secure V2.0
SNMP - Simple Network Management Protocol V2.0
LLDP - Link Layer Discovery Protocol V2.0
DCP - Discovery & Configuration Protocol V2.0
NTP - Network Time Protocol V2.0
ARP - Address Resolution Protocol V2.0

Further Information
More information about communications with the S7-1200 CPU is available in the S7-1200 manual in Entry ID: 91696622.