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RS232 maximum wire length

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shahramxyz

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rs232 cable length

Hi everybody;
I heard be4 that RS232 standard can work in 9600 baud only with 50 feet wire length .
But in a expriment I could send many corect data in 57600 baud (I think right number I wrote) with a 150 feet wire.
And also I read in an Article that the restriction depends on our hardware
please help is it true and if yes can I work with RS232 in 9600 baud and 150 feet wire length in an INDUSTRIAL state
Thx
 

rs232 length limit

In "noisy" industrial environment I wouldn't use RS-232 for distances more than the standard 50 feet for reliable transmission.
Try to implement RS-422 or RS-485, which use differential transmission and therefore are noise immune ..
It is possible that 150 feet will work correctly but you may face problems with ground loops and from time to time missed bits, or other unpredicted faults ..
Regards,
IanP
 

rs232 length

Hi;
I also test it with 60 meters cable some years ago.
it work very well! for confirmation purpose i masure it's waveform with oscilloscope. I dont find any distortion. its waveform (at reciever side) was very well!

Regards
 

rs232 maximum length

Words from the standard, ANSI/TIA/EIA-232-F-1997:

3.2 Cable Length
The maximum length of the cable is not defined; it is determined by the electrical requirement in 2.1.4 (see Annex A for guidance).

2.1.4 The load impedance of the receiver side of an interchange circuit is defined for an applied voltage range of 3 volts to 15 volts magnitude. It shall have a dc resistance of not less than 3000 ohms, nor more than 7000 ohms, measured with an applied voltage of 3 to 15 volts in magnitude. The effective shunt capacitance (CL) of the receiver side of an interchange circuit, including the capacitance of cable, measured at the interface point, shall not exceed 2500 picofarads. The reactive component of the load impedance shall not be inductive. The open circuit receiver voltage shall not exceed 2 volts in magnitude. (see 6.3, 6.4, and 6.5).

1.3 Data Signaling Rates
This standard is applicable for use at data signaling rates up to a nominal limit of 20,000 bits per second.
 

rs-232 cable length

It's about 16 m. at 20,000 bps. If use the low capacitance cable, it can be longer at 20,000 bps. And if use at lower speed the lenght can be longer.
 

rs232 max lenght

As specified by ANSI... 50m is for effecive communication with normal transmitter and receiver.

And you can use transmission beyond 50m , but it may results error in transmission. It purely depends on the environment your are transmiting and the material of the wire you are using.

It also depends on the sensitivity of your transmitting and receiving computer systems...
 

rs232 lenght

Which ANSI document says that?
 

max length rs232

I think this standard for cable lenght is in the worse case condition.
For example 5V line voltage (at Tx side), maximum capacitance, ....
In fact, practicaly, we can use very longer cable lenght.

Regards
 

rs232 maximum lenght

I use 5m cable for 115200 baud in noisy environment for many years
and different transeiver chips and never encountered a problem,
Varuzhan
 

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