Solved

HP Serial Port Problem

Posted on 2013-11-19
7
919 Views
Last Modified: 2013-11-23
I have HP EliteBook 8570p Notebook
The serial port on the laptop has a problem , when i connect any device to configure it on that serial port , the messages that have been output from the device appears normally , but when i tried to write anything via my keyboard it does not response to any key of keyboard ,  so the com port can read but cannot write.

Trouble Shooting:
1. i installed windows again , the same problem.
2. i used another software differ from hyper terminal , such like Tera term , putty , and the same.
3. i tried many routers , switches from different vendors to see if the problem from the device not the serial port of laptop , but the same
4. i've updated the bios and all the drivers to latest version , and the same.
0
Comment
Question by:EngAhmedFaris
  • 4
  • 3
7 Comments
 
LVL 13

Expert Comment

by:Norm Dickinson
ID: 39662167
Serial ports are pretty much the opposite of plug and play. You need to set the communications protocols for the particular device you are plugging into the port for speed, parity, stop bit, etc. and there are a lot of combinations. Both devices need to have the exact same settings for the communication to take place correctly. Here is a link to a basic guideline for setting serial communications:
http://www.mathworks.com/help/instrument/serialconfiguration.html
0
 

Author Comment

by:EngAhmedFaris
ID: 39662192
I already verify that the COM port has the same settings on the device need to be configured , but i think if there is mis-configuration it will not read from the device , but in my case the COM port read normally from the device but do not write any thing.
0
 
LVL 13

Expert Comment

by:Norm Dickinson
ID: 39662372
Perhaps you need a different cable? Some RS-232 cables do not carry all of the signals from end to end, but rather loop back on the same end to provide false feedback to the port.  See
http://pinouts.ru/SerialPorts/Serial9_pinout.shtml
http://pinouts.ru/SerialPorts/RS232_pinout.shtml
0
Better Security Awareness With Threat Intelligence

See how one of the leading financial services organizations uses Recorded Future as part of a holistic threat intelligence program to promote security awareness and proactively and efficiently identify threats.

 

Author Comment

by:EngAhmedFaris
ID: 39662694
I changed 3 console cables , and the same problem
0
 
LVL 13

Expert Comment

by:Norm Dickinson
ID: 39662819
Again, not all cables are designed for full communications across the cable from one end to the other, so it may not be a "bad" cable but one that is designed for only partial communication. It may be worthwhile to pin out the cable with an ohm-meter to determine whether the necessary pins on one end connect to the pins on the other end. Most inexpensive serial cables shortcut this by assuming there will be a signal, so some pins are not cabled thru, but instead the signal on one end is shorted to a different pin on the same end. It is a little confusing but this may help to explain it a little better.
http://www.lammertbies.nl/comm/cable/RS-232.html
0
 

Author Comment

by:EngAhmedFaris
ID: 39663033
I have usb to serial connector , and i used these cables with that connector and it works perfectly.
0
 
LVL 13

Accepted Solution

by:
Norm Dickinson earned 500 total points
ID: 39663464
Have you tested the port with a loopback plug and diagnostic software to see if in fact the hardware is functioning correctly?

http://www.ni.com/white-paper/3450/en/

http://www.reliableracing.com/downloads/LoopBackTest.pdf
0

Featured Post

Free Trending Threat Insights Every Day

Enhance your security with threat intelligence from the web. Get trending threat insights on hackers, exploits, and suspicious IP addresses delivered to your inbox with our free Cyber Daily.

Join & Write a Comment

Suggested Solutions

Every server (virtual or physical) needs a console: and the console can be provided through hardware directly connected, software for remote connections, local connections, through a KVM, etc. This document explains the different types of consol…
#Citrix #Citrix Netscaler #HTTP Compression #Load Balance
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…

746 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

12 Experts available now in Live!

Get 1:1 Help Now