Solved

serial port communication

Posted on 1998-08-11
3
274 Views
Last Modified: 2013-11-20
my windows app receives data from a photometrical device over the serial port and writes the data to a file.
I have a problem recognizing the stop of data transmission as there is no special character sent by the device
such as EOF. How can I recognize the end of data flow?
0
Comment
Question by:elazabi
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
3 Comments
 
LVL 6

Expert Comment

by:snoegler
ID: 1320562
If this device does not switch any status lines, like DTR or so, you will have NO possibility to
check this ... you have to rely on the data you get. Does the data format this device sends
allow an assumption about the end of the file? If not, another possibility would be to use a
timeout - i.e. when device sends continously data, then you may assume that a break of about
1000 msec ( which all users should accept without stopping your app) can be treated as
an EOF signal.
Fact is, without any information you can't get no information :)
0
 
LVL 1

Expert Comment

by:slinky
ID: 1320563
The may not be a special character at the end, but is there a typical pattern you can spot in the last part of the data?
Failing that, snoegler is right, timeout would be the way to go.
0
 
LVL 4

Accepted Solution

by:
piano_boxer earned 100 total points
ID: 1320564
What about delays inbetween messages.

<serial datapacket 1> <X ms delay> <serial datapacket 2>

If there is a delay, then you can use the interchar timeout value to determine when a complete packet has been received.
0

Featured Post

VIDEO: THE CONCERTO CLOUD FOR HEALTHCARE

Modern healthcare requires a modern cloud. View this brief video to understand how the Concerto Cloud for Healthcare can help your organization.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Introduction: Database storage, where is the exe actually on the disc? Playing a game selected randomly (how to generate random numbers).  Error trapping with try..catch to help the code run even if something goes wrong. Continuing from the seve…
In this post we will learn different types of Android Layout and some basics of an Android App.
This video will show you how to get GIT to work in Eclipse.   It will walk you through how to install the EGit plugin in eclipse and how to checkout an existing repository.
Monitoring a network: why having a policy is the best policy? Michael Kulchisky, MCSE, MCSA, MCP, VTSP, VSP, CCSP outlines the enormous benefits of having a policy-based approach when monitoring medium and large networks. Software utilized in this v…

636 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