Reading Ascii charactors from Parallel port???

[rt-runner]

Greetings:

I have a question about instructing a third party vender who is writing code in VB6.0. (windows XP sp2) 

They will be sending cycle counts thru the parallel port to my computer that i will be capturing using Labview 7.1.1 (windows XP sp2)

The format of the streaming will be Ex.   *000000324*000000325*000000326*... etc. Continuously

I can tell him to get rid of leading zeros if need be.

 I think i can capture this using VISA serial read.

a) But what should i tell the third party vender for him to write to the parallel port?  Also should set the printer port to RAW

    and/or bi-directional printing .

b) What is the pinout of the parallel cable between the two computers , is there a Null modem type of cable available, or is it pin to pin?

c) What about handshaking , such as printer not ready, buffer full, etc.etc.

Any help would be apreciated.

 Thanks

 Forrest 

fcampbell@swri.org

to modify thier software to a

Parallel port. so that i could capture.

I have a third party group that is running a process sending and receiving

 data

> thru a USB port for control of a frequency test. They are keeping track of

> cycle counts that

> are important in there test. They are using Visual Basic 6.0.

>

> What I want to do is to send the cycle counts ( which could be up to

> 999,999,999 cycles)

> (on an older system I would capture the cycle counts from a RS232 port

that

> they were send to me on another computer[Running Labview 7.1.1])

>

> I need ( since RS232 ports are sort of going away on new computer system

> nowadays) to capture a streaming cycle count from the third Party system.

...

> etc which will be continuous. They can modify there Visual Basic 6.0 to

> incorporate USB drivers for your chips. I will be capturing the Data

either

> RS232 or USB into Labview 7.1.1 .

>

> I noticed you had drives on your web site with VB and Labview.

>

> Could you guys give me some suggestions if possible.

> Thanks

>

>

[Ray.R]

I'm just a bit confused... below your message is something that describes RS232 & USBN communication.

Why would you want to send this over the parallel port?  Or it is a design constraint?

The reason for asking is that it is more common to do this over the serial port.

JLV

[rt-runner]

Greetings again:

 Sorry about the confusion, initially i was going to do this with a USB port or RS232 port.( I attached some previous messaging from before from another e--mail i had sent out to the third party group).

The third party group seems to be wanting a simple solution by sending there output to a printer port. To me this seems a little more complicated.

I would rather send to RS232 or USB between the two computers at 115k baud or faster. Maybe i can convince him differently if i had some example programs to send using USB and or RS232 in VB6.0. I do not have VB6.0 here and i do not want to do "none" Labview programming if possible.

So still my problem is to get labview to pick up the characters from a VB6.0 program sending to LPT1: Parallel port.

Thanks Forrest

[Ching_F.]

Hi Forrest,

Please take a look at this KnowledgeBase.  It has a lot of useful information about using parallel ports in LabVIEW.

If you do not find your answers in this document please do not hesitate to let me know by replying to this post.

[Ray.R]

Hi Forrest,

Okay... that makes more sense.  You are trying to communicate beetween 2 PC's.  Something like LapLink.. And yes, it would be okay to do this with the parallel port, it may have more speed than the serial port.  However for ease of implementation, you can use the serial port communication.  It is actually quite easy to implement. 

The first step (if you are using Windows), is to establish the communication between the PC's using Hyperterminal.  You should be able to "chat" between the 2 PC's.  Maybe I shouldn't use the word chat..  You can communicate (Tx/Rx - ASCII) between the 2 PC's.  Once you verify that this works (at the desired speed - and configuration), you can implement it in Labview. 

RayR

[rt-runner]

Ching:

This did not open:

"look at this KnowledgeBase"

What about the VB6.0 example program? any help on this ??

( such as any libraries etc.)

Thanks forrest

[Ching_F.]

Hi Forrest,

I am sorry about that.  Here is the link again.

As for VB 6.0 examples, you can take a look at this link.

Please let me know if that does not work or if you have any further questions.

Message Edited by cphuong on 04-18-2007 12:12 PM

[albertos]

Hi

I am also having a lot of trouble with the parallel port. I am writing an application to write throgh the data register and read from the status and control register. I have set my parallel port to standard mode (not Bidirectional, ECP or EPP). I use the inport and outport LV functions, however when it comes to read the control and status registers I cannot do so. I do not get any error at all. I have tried this application in 7.1 and 8.0.

Any comments?

REgards


Alberto

[Anna_M]

Hi Alberto,

You mentioned that you're not getting any error, so are you attempting to write to the register and then reading the register and your changes have not been updated?  Or is there some other method that you're using to show that the register is not being written properly?  As a starting point reference, have you had a chance to look at the examples included in LabVIEW for parallel port communication - you can find these by going to Help>>Find Examples and doing a search for "parallel".  This should give you results that include "Parallel Port Read and Write Loop.vi" and "Parallel Port Additional Data Register Inputs.vi".  Hope this helps!