×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

pros & cons of RS232 vs RS485 vs ethernet

pros & cons of RS232 vs RS485 vs ethernet

pros & cons of RS232 vs RS485 vs ethernet

(OP)
Hi all,

Thought I would post this question on eng tips. Can anyone explain the pros and cons of RS232 , RS 485 and ethernet comms protocols in terms of cost, speed, installation, ease of config, noise, cable distance...etc


 

RE: pros & cons of RS232 vs RS485 vs ethernet

As I posted on another topic, as good as EngTips is, there is not a lot of controls related traffic and it pains me to redirect from here.  But you may get a quicker answer at http://www.plctalk.net/qanda/
 

TygerDawg
Blue Technik LLC
Virtuoso Robotics Engineering
www.bluetechnik.com

RE: pros & cons of RS232 vs RS485 vs ethernet

Except for the fact RS-232 and RS-485 is cheaper there aren't any benefits.  I prefer RS-485 over RS-232 because it can be multi drop like Profibus DP and obvious much faster and able communicate at higher rates.

Ethernet rules.


 

Peter Nachtwey
Delta Computer Systems
http://www.deltamotion.com

 

RE: pros & cons of RS232 vs RS485 vs ethernet

Quick and dirty comparison of those 3 choices:
RS-232 = One device to one device, very close proximity, not a lot of noise. Speed = lowest. Implementation = easy. Cost = cheapest. Applications  = programing ports, one-to-one comms.

RS-485 = Multiple devices on one cable, more noise immune, thousands of feet. Speed = medium. Implementation = easy. Cost = cheap, but sometimes not as cheap as RS-232 if it was built-in (i.e. PCs). Applications = Small networked single point nodes, smart devices, SCADA, programming over small networks.

Ethernet = Virtually any number of devices, virtually unlimited distance (through various technologies), very noise immune. Speed = quantum faster than RS-485. Implementation = most difficult initially (but very common now). Cost = highest.
Applications = WANS, LANs, high speed nodes, long distance SCADA but it's often overkill for single point nodes.
 

"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln  
For the best use of Eng-Tips, please click here -> FAQ731-376: Eng-Tips.com Forum Policies  

RE: pros & cons of RS232 vs RS485 vs ethernet

There is one "quirk" I have run into with using Ethernet. If the backbone or transport for the ethernet signal is bandwidth limited, it is usually better to use a serial (RS-232, RS-485) type communication.
One example of this is ethernet radios on a licensed band. The radio bandwidth is usually very limited, about 9600 baud. Unfortunately to make the radio behave like an ethernet switch, some of that radio bandwidth is used as overhead. So you are better off using straight serial.

RE: pros & cons of RS232 vs RS485 vs ethernet

Quote:


There is one "quirk" I have run into with using Ethernet. If the backbone or transport for the ethernet signal is bandwidth limited, it is usually better to use a serial (RS-232, RS-485) type communication.
One example of this is ethernet radios on a licensed band. The radio bandwidth is usually very limited, about 9600 baud. Unfortunately to make the radio behave like an ethernet switch, some of that radio bandwidth is used as overhead. So you are better off using straight serial.
This is not "True" Ethernet, portal to portal.
This is like taking a fast train from NY to LA but swimming the Mississippi.  

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources