S7-300 PROFIBUS DP system configuration

PROFIBUS DP system configuration can be classified as DP master station system, CP Communications template main station system and intelligent slave DP systems. Three take DP master station system in the DP, CP Communications template main station system is basically the same hardware configuration.


1. the PROFIBUS DP systems: master/slave with DP systems


Take DP master/slave system design is very flexible, it allows the use of different data regions in the CPU to store the DP process data. Selection depends on the type of CPU and application of a data region. Process image, memory, and data blocks are available for DP input and output data.


Process image is the standard data distribution. CPU in the process image shall have sufficient space for the DP to keep a continuous input range and a continuous output of the area. This process may be affected by the central configuration image size and limit to the number of the signal module.


Memory with the same process image, the region for DP signal global storage. For example, if the space available to process images (the space not occupied by central signal module) isn’t enough, you can use the store.


Data blocks can also be used to store the DP signals. Best DP data relating to the area used a program called only this store.


F establishment of S7-300 PLC main station hardware configuration (DP): double-click the X2/DP” or CP342-5 column in the dialog box, select DP-Master


F add ET-200 at the PROFIBUS bus station:


Master/slave I/O addresses can not be duplicated, which is assigned by the system software. If a user needs to modify the address, you can reset the template properties dialog box.


2. PROFIBUS DP systems II: master station system with CP Communications template.


Communication templates CP master/slave system, master/slave I/O addresses can be repeated, because the PLC system is analogous to two CPU. Users can use the template properties dialog box to set I/O address, just within the master or the slave I/O addresses can not be duplicated.


When configuring when CP, you must set the operating mode. (Operating Mode)


CP342-5 DP DP-SEND and DP-RECV is always required. These chunks via the backplane bus transferring data between the CPU and CP.


Data CP342-5 is always a continuous transmission. Master the maximum data length is 240 bytes, maximum length is 86 bytes of data.


DP-SEND (send) specified in the CPU sends data to the PROFIBUS DP data area of CP‘s send buffer, for transmission to the DP Slave station; DP-RECV (receive) reads data from the DP Slave, PROFIBUSCP data into the CPU of the receive buffer specifies the DP in the data area.


DP-SEND (send) and DP-RECV (incoming) structures


DP-RECV (receive) the type and function of the Terminal parameters


DP-SEND (send) the type and function of the Terminal parameters


3. the PROFIBUS DP systems III: DP system with intelligent slave.


Intelligence from the station‘s main features are: DPmaster input/output data directly from the real input/output port, but from the preCPU.