Design Idea-serial port checks data address, sorts according

[ifithegr8]

Design Idea

i have 4 devices(weight indicator) that transmitt string contanig Adress of device i.eA or B and weight .if i connect all TX pins of devices and feed into RX pin of PC and they had to communicate to computer via RS232 port.
now i want to know is it possiable that i make some calculations in computer side that when serial port recives data it checks its address and sotre data in diff arrays according to adress.

one confusion in my mind is that devices send data simultaniusly so will there be any overlaping??


or else please send me some idea

 

[yashrolyan]

Re: Design Idea

1) if u will connect TX pin of all devices together then there shall be a overlapping resulting data corruption because at a time only one bit can there on bus. and in ur case all four weighing indicator will try to send their respective data on bus which will cause data overlapping so data corruption. that means u can not joint all TX line together in RS232 because RS232 provides on-to-one communication only.
For ur application u can do two one of thest two things
i) either use a string protocol at both end containing weight and address of deices, ur weighing indicator will work as slave and PC will work as master.PC will initiate the communication and will send a address of slave to which it want to communicate then the slave device containing the right will respond and wil send the data.by this process u can talk to individual indicator and can avoid overlaping


ii) to some different kind of protocol like RS485 or I2C................


best of luck

 

[madicalphy]

Re: Design Idea

Expansion of Input and Output (I/O) Lines of a micro-controller and method of communications, please have look on this.
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and
RS232 to RS485 converter related information on this page.
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simple introduction of rs-485 protocols,
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[ifithegr8]

Design Idea

but the problem is that my devices send data simultaneously i donot have to initiate transfer