serial transmission in 8051

[anboli]

hi everybody i having a small doubt,

i had interfaced the several clocks with one master clock, all the clocks are have to run in a same time in synchronize manner.

but in these what is the problem means, while im moving slave clock to long range approximately(100m), then the slave clock getting slow and not synchronizing with the master clock.

i using a 889s52 controller transmitting the data's through max232 for all the slaves.

what my doubt means whether i can use the buffer IC inbetween the line or else it have any idea to synchronize the clock for the given range. or whether i need to give some rs232 line repeatedly for every 10m?


please suggest me any idea.

 

[hate]

What kind of synchronization are you expecting, can you please go into more detail? Like for example does all the slaves use the same clock to communicate with each other through UART, I2C etc...?

 

[anboli]

its working with the UART transmission.

from the master clock all the time values are send to every slave clocks. but its getting delay with each and every one.

 

[rajudp]

you are using one transmitter and receive in some receivers, there wont be a noticeable delay , at what rate you are communicating ( transmitting )?

 

[anboli]

im using only one transmitter and it receiving upto 14 receivers(slave clock). and one point, nearest slave clocks are working, and longest only getting trouble.

and im using 9600 baud rate.

 

[hate]

its working with the UART transmission.

from the master clock all the time values are send to every slave clocks. but its getting delay with each and every one.

I guess you are trying to say that master clock provides the system clock for all slaves and I'm not talking about the UART transmission here. If that's the case, what type of a clock signal are you providing to the slaves? There is a certain minimum for the clock frequency which the receiving side of the UART must be running at (the slaves in your case) and that's faster than the needed transmitter clock. Can you provide a schematic of your connections?

 

[rajudp]

seams like rf transmitter range problem

 

[anboli]

and also i having one doubt, the master clock is configured by RS 485, and slaves are in rs232 configurations, and nearest slaves are working. and i referred from the net, that rs232 will transmit and receive upto 15m only, so we can go to rs485 for the longest distance. so im gono to try with rs 485 for all the slaves.