Availability
The MPI/DP interface of an S7-400 CPU in the factory state is set as an MPI interface with an address of 2.
Properties
The MPI represents the CPU interface for PG/OP connections or for communication on an MPI subnet.
The preset transmission rate for all CPUs is 187.5 Kbps. The maximum transmission rate is 12 Mbps.
The CPU automatically broadcasts its configured bus parameters via the MPI interface (the baud rate, for example). A programming device, for example, can thus receive the correct parameters and automatically connect to a MPI subnet.
Note
In runtime, you may only connect programming devices to an MPI subnet.
Other stations, such as OP or TP, should not be connected to the MPI subnet in runtime.
Otherwise, transferred data might be corrupted due to interference pulses or global data packages may be lost.
Time synchronization
Time synchronization is possible by using the MPI interface of the CPU. The CPU can be master or slave.
MPI Interface as a PROFIBUS DP Interface
You can also configure the MPI interface for operation as a PROFIBUS DP interface. To do so, you can reconfigure the MPI interface under STEP 7 in HW Config. You can use this to set up a DP line consisting of up to 32 slaves.
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Communication 4.1 interfaces
S7-400 Automation System, CPU Specifications
4-2 Manual, 11/2006, A5E00850746-02
Devices capable of MPI communication
• PG/PC
• OP/TP
• S7-300 / S7-400 with MPI interface
• S7-200 only with 19.2 Kbps and 187.5 Kbps
4.1.2 PROFIBUS DP
Availability
The CPUs 41x-2, 41x-3 and 417-4 have an integrated PROFIBUS DP interface. There are also PROFIBUS DP interfaces in the form of plug-in submodules for the CPUs 41x-3, 41x-4 and for CPUs with the suffix "PN/DP".
To be able to use these interfaces, you must first configure them HW Config and then download the configuration to the CPU.
A CPU with MPI/DP interface is always configured as an MPI configuration as the factory setting. To use it as a DP interface, you must reconfigure the MPI/DP interface as a DP interface in STEP 7.
Properties
The PROFIBUS DP interface is mainly used to connect distributed I/O. You can configure the PROFIBUS DP interface as master or slave. It allows a transmission rate of up to 12 Mbps.
The CPU broadcasts its bus parameters, such as the transmission rate, via the PROFIBUS DP interface when master mode is set. A programming device, for example, can thus receive the correct parameters and automatically connect to a PROFIBUS subnet.
Note
For DP interface in slave mode only
When you disable the Commissioning / Debug mode / Routing check box in the DP interface properties dialog in STEP 7, all user-specific transmission rate settings will be ignored, and the transmission rate of the master is automatically set instead. This disables the routing function at this interface.
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Communication 4.1 interfaces
Time synchronization via PROFIBUS DP
As the time master, the CPU sends synchronization message frames to the PROFIBUS to synchronize further stations.
In its capacity as the slave clock, the CPU receives synchronization message frames from other time-of-day masters. One of the following devices can be a time master:
• A CPU 41x with internal PROFIBUS interface
• A CPU 41x with external PROFIBUS interface, for example CP 443-5
• A PC with a CP 5613 or CP 5614
Devices capable of PROFIBUS DP communication
The PROFIBUS DP interface is used to set up a PROFIBUS master system or to connect PROFIBUS I/O devices.
The following devices can be connected to the PROFIBUS DP interface:
• PG/PC
• OP/TP
• PROFIBUS DP slaves
• PROFIBUS DP master
The CPU is then used either as a DP master or as a DP slave which is connected via PROFIBUS DP field bus to the passive slave stations or other DP masters.
Some devices use the 24 VDC power supply of the interface. This voltage is provided at the PROFIBUS DP interface connected to a reference potential.
Reference
Further information on PROFIBUS: http://www.profibus.com
长沙工控帮教育科技有限公司整理
Communication 4.1 interfaces
S7-400 Automation System, CPU Specifications
4-4 Manual, 11/2006, A5E00850746-02
4.1.3 PROFINET
Availability
CPUs with a "PN/DP" suffix have an ETHERNET interface with PROFINET functionality.
Assigning an IP Address
You have the following options to assign an IP address to the Ethernet interface:
1. With the SIMATIC Manager command "PLC -> Edit Ethernet Node".
2. With the CPU properties in HW Config. Then download the configuration to the CPU.
Devices Capable of PROFINET (PN) Communication
• Programming device/PC with Ethernet network card and TCP protocol
• Active network components (Scalance X200, for example)
• S7-300 / S7-400 with Ethernet CP (for example, CPU 416-2 with CP 443-1)
• PROFINET IO devices (for example, IM 151-3 PN in an ET 200S)
• PROFINET CBA components
Connectors
Always use RJ45 connectors to connect devices to the PROFINET interface.
Properties of the PROFINET Interface
Protocols and communication functions PROFINET IO
PROFINET CBA
IEC61784-2 , Conformance Class A, B and C Open block communication via
• TCP
• UDP
• ISO on TCP S7 communication
Programming device functions SNMP
LLDP
Time synchronization using the NTP method as a client
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Communication 4.1 interfaces
Connection
Connector design 2 x RJ45
Switch with 2 ports
Media Twisted pair Cat5
Transmission speed 10/100 Mbit/s
Autosensing Autocrossing Autonegotiation
Note
Networking PROFINET Components
Full duplex mode with 100 Mbps is mandatory for PROFINET IO.
Reference
• For further information on PROFINET, refer to PROFINET System Description
• For detailed information about Ethernet networks, network configuration and network components refer to the SIMATIC NET manual: Twisted-Pair and Fiber Optic
Networks,available under article ID 8763736 at http://support.automation.siemens.com.
• Component Based Automation, Commissioning SIMATIC iMap Systems - Tutorial, Article ID 18403908
Further information about PROFINET: http://www.profinet.com
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Communication
4.2 Communication services
S7-400 Automation System, CPU Specifications
4-6 Manual, 11/2006, A5E00850746-02