The Siemens S7-200 supports a variety of communication modes, such as point-to-point interface (PPI), multipoint interface (MPI), and Rrofibus DP. Communication protocols such as PPI are mainly used for communication between Siemens products and programming of plc. In the free port mode, the user can control the serial communication interface to implement a user-defined communication protocol. The user can use the ladder program to call the receive interrupt, send interrupt, send command (XMT), accept command (RCV) to control the communication operation. In free port mode, the communication protocol is completely controlled by the ladder program.
The communication port on the S7-200 CPU is a 9-pin D-type connector compatible with RS-485. The PLC also provides a PC/PPI cable that connects RS-485 to the RS-232C on the PC. It can be easily implemented with S7. Hardware connection between -200 series PLC and PC.
The programming software of S7-200 is STEP7-Micro/WIN32. The software has three programming modes: STL, FBD and Ladder. There are two kinds of instructions: SIMATIC instruction and IEC131-3 instruction. The example given in this article is STL programming using SIMATIC instructions.
Implementation of communication program on S7-200 PLC
The PLC program is divided into a main program and an interrupt program. The main program completes the functions of initializing the communication port, opening the interrupt, judging, and transmitting data, and interrupts the function of receiving and transmitting data. The receive command (RCV) initiates or terminates the receive message function, and must specify start and end conditions for the receive operation. The send command (XMT) relies on the communication port to send data in free port mode.
The selection of the control word reflects the special memory bit of the current position of the mode switch of the CPU operating mode as SM0.7, which controls the entry of the free port mode. When SM0.7 is 0, the mode switch is in the TREM position; when SM0.7 is 1, the mode switch is in the RUN position. Free port communication is allowed only when the mode switch is in the RUN position. SMB30 is the free port mode control byte, used to set the communication parameters such as calibration mode, communication protocol, baud rate (see the related books for the setting of other control words).
Some brief introductions to the program
NETWORK1
LD SM0.1 // first scan
MOVB 16#09, SMB30
/ / Free port communication mode: 9600 baud rate, no parity, 8 data bits
MOVB 16#7C, SMB87 // Receive message status byte
MOVB 16#53, SMB88
/ / Set the start character of the message "S"
MOVB 16#45, SMB89
/ / Set the end of the message "E"
MOVW +5, SMW90
/ / Set the interval of idle lines (ms)
MOVW +179, SMW92
//Intercharacter/information timer timeout value (ms)
MOVB 60, SMB94 //Number of characters received
NETWORK2
LD SM0.1 MOVB 16#53, VB2499
/ / Set the first address of the receive and send buffer
ATCH sent interrupt, 9
/ / Connect the send completion interrupt and send completion interrupt subroutine
ATCH receives the interrupt, 23
/ / Connect the receive completion interrupt and receive completion interrupt subroutine
ENI //Allow interrupts
Antenk DIN41612 Connectors are a versatile two piece PCB connector set with feaures useful for many applications including connections for plug-in card and back-panel wiring, PCB to PCB attachment and peripheral connections for external interfaces. Features include a multitude of body sizes and styles with options that include selective contact loading, make and break contacts, contact lead length choices and contact plating variations each in .100" [2.54mm] or .200" [5.08mm] centerline spacing.
The DIN 41612 standard covers a series of two-piece backplane connectors widely used in rack-based telecommunication, computing, process control, medical, industrial automation, test and measurement and military/aerospace systems where long-term reliability is required. They consist of one to three rows of contacts in combinations of 16, 32, 48, 64, or 96 contacts on a 0.1-inch (2.54 mm) grid pitch. The 3 rows are labelled a, b and c and connectors up to 64 way if using a 96 way body can use either rows a+b or a+c. DIN 41612 Signal connectors can be rated to 1.5 amps per signal pin, at 500 volts, although these figures may be de-rated according to safety requirements or environmental conditions. Several hybrid power and coaxial configurations are available that can handle up to 5.6A or even 15A. This wealth of variations explains the very wide range of applications that they`re put to. For over 30 years these DIN 41612 `Euro Card` connectors to IEC 60603-2 have offered a highly reliable system for board interconnects. Precision contact density, low mating forces, a two piece protective design and many contact termination styles offer unlimited design opportunities. Termination methods include – straight PC, solder eyelet, wire wrap, crimp and [press fit" terminals. Insertion and removal force are controlled, and three durability grades are available. Standardisation of the connectors is a prerequisite for open systems, where users expect components from different suppliers to operate together; ept and Conec DIN 41612 are therefore fully intermateable with all other similarly compliant products from other manufacturers like Harting, Erni, Hirose and TE Connectivity, etc.
The most common connector in the DIN product line is type C, which is widely used in VMEbus systems, the DIN 41612 standard has been upgraded to meet international standards IEC 60603-2 and EN 60603-2. In the past, ept used a comb supported press-fit tool for their type C and B press-fit female connectors. To be more competitive, ept has changed to flat-rock technology (just a flat piece of steel pushed on the top of the connector) as used by many other manufacturers.
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Types
Number of contacts varies
Many variations of housing material, including different types of metal and plastic
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Male and female
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H, F, H+F & M type DIN41612 Connectors
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Female Cable Connector
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The primary use of DIN 41612 connectors are PCB Connectors and motherboards, the main acceptance would be their board to board reliable connections.
Applications of Din41612 Connector:
Applications
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industrial control
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This is not a definitive list of applications for this product. It represents some of the more common uses.
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