Solved

Parallel port communication using Java Comm

Posted on 2001-06-02
4
332 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
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

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

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

Suggested Solutions

Title # Comments Views Activity
groupSum5 challenge 5 68
VB Script to add site to Java Exception List 4 49
reverse digits of a number using for loop 5 36
servlet example issue 6 29
After being asked a question last year, I went into one of my moods where I did some research and code just for the fun and learning of it all.  Subsequently, from this journey, I put together this article on "Range Searching Using Visual Basic.NET …
Go is an acronym of golang, is a programming language developed Google in 2007. Go is a new language that is mostly in the C family, with significant input from Pascal/Modula/Oberon family. Hence Go arisen as low-level language with fast compilation…
Viewers learn about the “while” loop and how to utilize it correctly in Java. Additionally, viewers begin exploring how to include conditional statements within a while loop and avoid an endless loop. Define While Loop: Basic Example: Explanatio…
This tutorial covers a step-by-step guide to install VisualVM launcher in eclipse.

911 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

20 Experts available now in Live!

Get 1:1 Help Now