Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

Parallel port communication using Java Comm

Posted on 2001-06-02
4
Medium Priority
?
346 Views
Last Modified: 2012-06-27
When we write on the parallel port using ParallelPort.getoutputStream().write(byte) then the signal DOESNOT appear on the pins but if we connect the port with the printer then the printer prints the data byte.
Is there any acknowledgement signal back from the printer which allows the port to make the data byte appear on the pins.
We cannot change the Mode of the Port other than SPP to ECP or EPP or other through Java Comm, although we have changed the Mode in the ROM BIOS.
We want the data byte to appear on the pins as soon as the write method is called. Right now our application stucks after calling the write method if printer is not connected.
0
Comment
Question by:alinasim
[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
4 Comments
 

Expert Comment

by:megloff
ID: 6150199
yes there are some callback of the printer. Have you tried with othe rpogramming languages like "c" ?. I can't remember that we have to set up any control register that the output will apear at the pins. So this is the strange part about it.

Perhaps it could be that the Java API internal first will receive a control signal before it writes an output. So make sure which signal could be this. There are 5 control Signals.

Error (-) Pin 15  ..... Failure
SLCT (+) Pin 13   ..... printer online
PE (+)  Pin 12    ..... paper error
ACK (-) Pin 10    ..... Acknowledge
Busy (-) Pin 11   ..... Printer is busy

(-) negative logic, active (bit is set)  is when 0V DC
(+) positive logic, active (bit is  set) is when 5V DC

I guess the SLCT or Busy could disturb your output. Take
a Voltmeter and measure the signals at your printer communication. Try also a little "c" application to see if this is always the problem.


 

0
 

Author Comment

by:alinasim
ID: 6156952
With C language there is no problem in getting the data onthe pins. it is working with C language.
Maybe we'll have to use JNI to map the C function with the java Native Method. But doing it using JavaCOMM still remains my question ?
0
 
LVL 5

Expert Comment

by:vemul
ID: 7752131
No comment has been added lately, so it's time to clean up this TA.
I will leave a recommendation in the Cleanup topic area that this question is:

- To be PAQ'ed and points refunded

Please leave any comments here within the
next seven days.

PLEASE DO NOT ACCEPT THIS COMMENT AS AN ANSWER !

vemul
Cleanup Volunteer
0
 

Accepted Solution

by:
Banath earned 0 total points
ID: 7842824
Per recommendation - PAQ'ed and points refunded

Banath
EE Moderator
0

Featured Post

The top UI technologies you need to be aware of

An important part of the job as a front-end developer is to stay up to date and in contact with new tools, trends and workflows. That’s why you cannot miss this upcoming webinar to explore the latest trends in UI technologies!

Question has a verified solution.

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

INTRODUCTION Working with files is a moderately common task in Java.  For most projects hard coding the file names, using parameters in configuration files, or using command-line arguments is sufficient.   However, when your application has vi…
Introduction This article is the second of three articles that explain why and how the Experts Exchange QA Team does test automation for our web site. This article covers the basic installation and configuration of the test automation tools used by…
Viewers learn how to read error messages and identify possible mistakes that could cause hours of frustration. Coding is as much about debugging your code as it is about writing it. Define Error Message: Line Numbers: Type of Error: Break Down…
Viewers will learn about the regular for loop in Java and how to use it. Definition: Break the for loop down into 3 parts: Syntax when using for loops: Example using a for loop:
Suggested Courses

715 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