Is VISA Write VI / Out Port (need AccessHW) better for writing to parallel port?

We have experimented with 2 methods for writing to parallel port:
1. Using NI VISA directly by calling VISA Write vi.
2. Using the Out Port vi, for which we had to install AccessHW.
Does the first method have any disadvantages. It seems to be a simpler solution.
Operating system: Windows 2000
Labview 8.2
NI VISA 4.0

Hey rashadi,
There is nothing wrong with using the VISA write.vi to write to a parallel port. Here is a great example program of how to use the VISA vi's to write to a parallel port.
I hope this helps!
Best regards,
Jason W
Applications Engineering
National Instruments

Similar Messages

Satellite M45-S169 PSM43U: need to connect to a serial & parallel port

Hello!
I have an old model of Satellite and I need to connect it with a machine that has old fashioned entrences, with pins (mother and father) and was told that I need a replicator (serial and paralell).
Now, I'm very confused because I'm not technical so please advise me on two things: is there something that does such thing? (usb to old fashion pins) and if there is I really need to buy it (so please pusrchase details).
Sorry if I've been so bad at describing what I need. I'm an electronist and am working with big machines therefore I need to connect my laptop to the machine;s software.
Thank you

Hmm. The new-age generation notebooks dont support the serial or parallel ports
Therefore youve got not many possibilities to connect a older devices to a notebook which was not equipped with the serial or parallel port.
As far as I know there are some USB-to-serial or USB-to-parallel port adapters.
Google a little bit and Im sure you will find some good offers.
But note; I read somewhere that not all adapters work properly you will have to investigate a little bit.
Good luck

Reading/writing to parallel port LabVIEW 7.0 Win2000

I'm using LabVIEW 7.0 on a Windows 2000 machine which also has the CVI runtime engine version 6.0.4.105.
I wish to write to the parallel port, simply on/off signal to eight lines. I have previously done this with LabVIEW 5+Win98. I have downloaded the accessHW libraries and installed them but have discovered that I also need the CVI rte version 5.0 . When IT personnel try to install this run time engine "A newer version of this run time engine is currently installed"
appears and won't install version 5 over version 6. Has anyone else come up against this and is there a way around this (without having to install an older version of LabVIEW)?

Leeser wrote:
> I'm using LabVIEW 7.0 on a Windows 2000 machine which also has the CVI
> runtime engine version 6.0.4.105.
> I wish to write to the parallel port, simply on/off signal to eight
> lines. I have previously done this with LabVIEW 5+Win98. I have
> downloaded the accessHW libraries and installed them but have
> discovered that I also need the CVI rte version 5.0 . When IT
> personnel try to install this run time engine "A newer version of this
> run time engine is currently installed"
> appears and won't install version 5 over version 6. Has anyone else
> come up against this and is there a way around this (without having to
> install an older version of LabVIEW)?
You could also use the PortIO library from the OpenG project
http://www.openg.org.
It is currently only in the CVS source code
repository on that site and not yet part of the OpenG Toolkit. Because
it is not everybodys thing to use CVS I include that library as
attachement here.
I tested it myself on Win95, NT4, 2000 and XP and had no problems at all
with it. But please consider it beta software and if you have problems
let me know with as much details as possible.
Rolf Kalbermatter
Rolf Kalbermatter
CIT Engineering Netherlands
a division of Test & Measurement Solutions
Attachments:
portio.zip ‏195 KB

Writing to parallel port

i need to be able to write to the parallel port on a desktop computer
to control a stepper motor. I need to be able to write logic high and
low
at certain pins that go to a stepper motor driver. The writing to the
port needs to be done so many times, or so many steps that are entered
into the interface. Pins7 is the clock that that starts the stepper
motor control in the stepper motor driver. Also, pins 9 and 10 need
to be driven low or high to tell driver wether half or full step and counter clockwise or clockwise.
Basically i need to know how to set up my parallel port on my labtop in labView 7.1?
I want to be able to use the write to digital I/O.vi to send the proper
binary or hex value of an index array to the parallel port
to drive the motor driver.

Hi exavier,
Look here maybe someone else hase asked.
Ton
Free Code Capture Tool! Version 2.1.3 with comments, web-upload, back-save and snippets!
Nederlandse LabVIEW user groep www.lvug.nl
My LabVIEW Ideas
LabVIEW, programming like it should be!

I need to use my LaserJet 4 (parallel port) on my new HP computer (VISTA - no parallet port ,all USB

I was using a parallel to USB cable, but for some reason it stopped working.

This seems to be a commercial product. For the best chance at finding a solution I would suggest posting in the forum for HP Business Support!
You can find the Commercial Laserjet board here:
http://h30499.www3.hp.com/t5/Printers-LaserJet/bd-p/bsc-413
Best of Luck!
You can say thanks by clicking the Kudos Star in my post. If my post resolves your problem, please mark it as Accepted Solution so others can benefit too.

Comms with parallel port

Hi
I am trying to send a command to a printer via the parallel port, but am having no joy. I have set the BIOS printer port setting to 'Bidirectional', and created a small test program as attached.
I need to send an <ESC>A, 10 (hex), <ESC>Z in order to stop the printer during a print run, and an <ESC>A, 11 (hex), <ESC>Z to restart the printer. I have used the functions found in the example, but maybe I'm misunderstanding the functionality of the functions?
Attachments:
Test LPT1 commands for prn stop-start.vi ‏68 KB

Hi Alan,
I was working on a windows 2000 sending a signal to the parallel port using a Out Port.VI and it worked fine because the format of the computer was a 378 like you have in your program; however, when i tried to use this program in a windows vista, this didnt work because the format of the parallel port of this computer was BD00-BD07, which is not written in 16 bit like your program. In order to solve this problem, i used VISA Write and it would automatically send the signal to the parallel port. Try using VISA and you shouldnt have any problems. I will send you an example VI so you can see how i used it. I also modified your VI using VISA instead of using Out Port.vi. It has an error because part of the file is missing but this should get you started. If you have any questions dont hesitate to ask.
Guillermo Naranjo
Attachments:
UsingVISA.vi ‏11 KB
Modified Test LPT1 commands for prn stop-start.vi ‏19 KB

Problems Reading/Writing Parallel Port Data, Status & control Registers Using In Port.vi and Out port.vi

Hi,
Can anyone there help me Please with the problem. I am trying to
communicate with the parallel port using my program which i have
attached to the message. I am running LabVIEW 7.0 Professional with
application builder. All the program does is reads and writes to the
three parallel port registers. It runs FINE!!! in my computer. But when
i built an executable (see attached) and tried running on a different
computer (with LabVIEW Runtime engine 7.0 installed) the program does
not read/write to the registers. The target PC had the parallel port in
SPP mode just like mine. I can't seem to understand whats going wrong?
Can anyone please help me if you know the right answer.
Thanks
Attachments:
Programs.zip ‏119 KB

Hi Guys,
I too have a problem using "Out Port.vi", but of a diferent kind. I use this VI to control the Parallel Port which in turn controls a small circuit. I use only two data pins, DP-2 and DP-4 for this purpouse. I use LV 7.1 Professional Development version in a Windows 2000 operating system. Now, my main problem is that my code runs fine (both is development and .exe forms) in my development computer, but when I try to run the .exe version in other computers (Windows XP operating system), it asks for a "protocol file" while starting (look at the attached picture).
Now, I really have no idea what kind of a protocol file it asks for and just click "ok" and proceed to work, the most interesting part is that the code works well as I expected. So, my only problem is that it asks for a protocl file which I want to avoid. As with the application building, I do all that is required like including the sub VIs (self developed), creating an installer, enabling the port access, and creating a proper .ini fine. I also use the Out Port.vi from the AccessHW library.
I have my doubts on two fronts,
1) With the version conflict, since my development computer runs with Windows 2000 and my target computers all run with Windows XP
2) With the Out Port.vi which further contains a small VI "Output Word to Port.vi" in it and that further contains Call Library Function Node, which might call soem external files, like what my problem is.(look at the attached picture)
I don't have answers to these questions and may be my problem is in different place, but I would like to hear from anyone who could give me a helping hand. I am in a situation where I could not disclose my code.
Thanks in advance,
mohan
Attachments:
protocol file.zip ‏153 KB

VISA Read Timeout and VISA Write not working

I'm writing a program that sets a triangle wave pattern voltage (using Triangle Wave VI) to a DC power source (GWInstek PST-3202) through a RS-232 connection. I know my instrument parameters are set up correctly because I've been able to control this power source using a different VI with the same parameters. I also know I am connected to the power source because I can talk to it using MAX. I have a string indicator before my VISA Write statement that shows me the command being sent to VISA Write. It shows the correct syntax for setting a voltage on this instrument. However, when I run the VI, the voltage is not changed on my instrument, even though the correct command is sent to the instrument. After the VISA Write operation I have inserted a VISA Read function in order to read the newly set voltage from both a numeric and a waveform indicator. Using the Error Out cluster I am able to see that there is a timeout error from VISA Read. I thought perhaps I needed to clear or flush the buffer after each Read statement, but that didn't work either. I'm stumped as to why VISA Write isn't writing to the device. I have included my VI below, as well as the initialization subVI for the power supply.
Attachments:
Triangle Volt Mod.vi ‏27 KB
GW Instek initialization.vi ‏18 KB

Yep, you need to append the End of Line character to the end of your command. And for your read to work properly, you need to request the data. That requires a querry command to be sent. Look closely at the differences in command and communication structures between your working VI and your mod.
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
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Sending out a signal via Parallel port in interrupt mode?

I am trying to send out a 5KHz TTL signal via parallel port. the CPU should be disturbed at most time. so we can't use loop structure. I guess I have to use interrupt mode to do this job.
In other languages, we might be able to programm 8253, which is a timer and counter chip on mother board. can we generate a 5KHz siganl via parallel port without disturbing CPU?
or can we call another labview program in our main labview program.by doing so, two programs are running at the same time, we may be able to solve my problem
Thanks

Hi Sean-
This functionality is theoretically possible, but this might not be the best option if you are concerned about latency in operation. A few references for using the parallel port in LabVIEW are linked in this thread.
If you are concerned about precise timing and operating system latency issues, you may want to consider a hardware-timed PCI counter/timer board instead. This utility is a good starting point for selecting such a card.
Tom W
National Instruments

How should I develop Level Controller using Parallel port(Printer port)

I need to develop a level controller using parallel port of my computer with a third party Data Acquisition Device. Is it possible to do it with In and out port vi in labView 7.1. Please guide me how can should I configure these Vis to write control data and then receive level transmitteed data through parallel Port(Printer port). My third party DAQ has two analog input channel and one analog output channel.

Dennis Knuston
I have uploded the details of that third party daq in another thread please see that and tell wether this type of daq requires driver software
http://forums.ni.com/t5/Multifunction-DAQ/Parallel-port-based-daq-and-drivers/m-p/1819997

Parallel port under linux

could anybody help a linux-labview beginner?
i'm trying to write to my parallel port. but labview is obviousely not set
up for this. does anywone happen to have a vi which can do that?
best of regards
michael h. fischer
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"michael h. fischer" writes:
> maybe i didn't comunicate here.
> i don't intend to print anything out but i want to set each pin of the port
> hi or low. i'm trying to turn some electrical relay-switches on and off.
>
> thanks anyway, all these hints are useful to me
Michael,
So using an true ASCII printer or dircetly /dev/lpx is the easiest
solution. Just "print" the ASCII charakter representing the bits to
set.
Johannes Nieß
>
> "Johannes Niess" wrote in message
> news:[email protected]..
> > "michael h. fischer" writes:
> >
> > > could anybody help a linux-labview beginner?
> > > i'm trying to write to my parallel port. bu
t labview is obviousely not
> set
> > > up for this. does anywone happen to have a vi which can do that?
> >
> > Michael,
> >
> > I'm not sure how you adress the parallel port.
> >
> > Writing directly to an I/O port is not allowed for security
> > reasons. There are VI's to do the required system calls.
> >
> > You might be able to use the (old) serial VI's with a high serial port
> > number. You can look up the port number on a LV version for Windows.
> >
> > I'd use a completely different strategy: VISA can address parallel
> > ports. With Windows you just use ASRL10. You might need some tweaking
> > of the VISA preferences files to do it.
> >
> > Printing data to a parallel port should be done with the tools
> > designed for it: System Exec: lpr file.txt
> >
> > Does someone have a summary of the options for reading the parallel
> > port and setting control lines via the described methods?
> >
> > Johannes Nieß

[WinXP/LabView7.0]Reading parallel port is too slow...

Hi,
First I would like to apologize for my English. I'm from Switzerland....
I'm trying to read out a 16Bit A/D in 1us steps. Serial Communication over a PIC is too slow, so I was looking for a faster option. I found out there is possibility to read from the parallel port:
I downloaded and installed the AccessHW drivers. I found 2 Vi's (see attached files) to read and write to the port. But this works only very slow. (100Hz read frequency).
By the way I need some advice how to use 16 bits in minimum as inputs. When I set the bit 5 in Baseregister+2 I can read the Baseregister. I can read the whole byte except bit 3. This bit stays always high (3.4 VDC).
The 5 status bits from Baseregister+1 I can
read with no problems but the read frequency is around 100Hz too...
The 4 control bits from Baseregister+2 I can't access. I followed the instructions in this link: http://zone.ni.com/devzone/conceptd.nsf/webmain/72C6FC6CE4AD4D1386256B1800794596?opendocument#4 to make this 4 bits inputs, but it doesn't work. I set the Baseregister+2 00100100 (all of the 4 bits are high) and then I start to read out the Baseregister+2, but there are no changes, when I connect one of the 4 pins to ground.
Hope there is anyone who can help me..!
Greets
Attachments:
Input_Byte_From_Port.vi ‏20 KB
Output_Byte_To_Port.vi ‏12 KB

If you're trying to acquire a 16-bit sample at 1MS/s, using the parallel port, it will not work. In fact, many full-fledged DAQ cards do not support this high sampling-rate/resolution combination. Look at what NI has available here, in the S and E series DAQ boards--this should give you a feel for what's out there and what a professionally manufactured piece of equipment is capable of:
http://sine.ni.com/apps/we/nioc.vp?cid=10955〈=US
http://sine.ni.com/apps/we/nioc.vp?cid=1038〈=US
As you noted already, a parellel port is going to be extremely slow for your needs, and likely not only be slow, but also have a pretty fair amount of timing jitter, since the timing of your read calls will be indeterminate. I would definitely recommend you look into som
e other hardware acquisition option besides your parallel port... it won't get you very far unfortunately, because that isn't what it's really designed for.

Using Parallel Port with Outport.vi Problem

Hello,
I am trying to use my parallel port to control a relay network and have run into a problem. I am using the outport instead of visa because for some reason I get an error with visa and outport seems more simple. The problem I am having is that my program doesn't seem to be able to initially take control of the port. What I mean by this is that if I restart the computer and open/run my program, I get an incorrect output on the parallel port. However, if I run one of the example programs for controlling the paralle port using outport (attached) (I believe the one I use is called Reading and writing to parallel port using loops) I am able to control the output to the parallel port. Also, after the example has run, my program works correctly. However, if I restart my computer again and run my program first it can no longer control the port correctly. So the problem seems to be that my program isn't initializing the port correctly or assessing it right at the beginning of the program. However, looking at the example program I don't really see what they are doing that I am not. I have the correct port address.
My program takes values from a text file and displays them on the port and that works correctly.
Attachments:
CircuitTopModule.vi ‏26 KB
parallel port examples.llb ‏72 KB

Hi Jag213, I'm glad you were able to resolve the issues you discussed on the other forum related to this issue.
Now that you have it working, I would recommend a few things:
1. Just try modifying one of the existing examples and see what you can get away with removing in order to keep it working the first time.
2. Try modifying the timing on your example - 10 seconds is a long time to wait between each week, I wonder if you are getting a time out? Do the examples work when you insert that kind of timing delay?
3. Add the In Port.vi into your code - this may be related to getting your Out Port.vi to work correctly.
4. Your code controls 8-bits on the parallel port, while the examples control 32-bits. Do all 32 bits need to be initalized? Looking at the Parellel Port Read and Write Loop.vi Example, in the IO Connector Status, the 31st bit controls whether the target is initialized.
Play with these settings and see if you can get yours to work the first. If all else fails, build your program to run off of one of the examples. For example, have the while loop run once, and then call yours as a SubVI.
Good luck!
Joey S.
Software Product Manager
National Instruments

Writing a String to the Parallel Port

I am a new user of Labview and have very little experience. I am trying
to write an arbitrary string (that I can input) to the parallel port.
Basically, I need to communicate with a device that connects to it and
will accept commands as plain strings. I have read the article "using
the parallel port with labview" but it hasn't helped me as I am so
inexperienced. I was hoping that someone could help to learn how to do
this and if there's a vi that already does this. It seems like a simple
enough task. Thanks.

Rather than simply present an answer from which you will learn little, I will try and out line what it is that you should investigate......
First have a look at a string control
You might want a button and a case structure to tell the code when to start decoding the string
Put the following code inside the case structure say on the true state
Then, taking data from this string control get the strings length
Then using this and a loop index through the string using the string subset VI on the string pallette, use the length of 1 and index the position in the loop
Now figure out how to convert the character to an ASCII value
Send this to the parallel port
This should be a reasonable frame work to empower you to learn for yourself.
"Give a man a fish and you feed him for a day, teach a man to fish and you feed him for life", enjoy the free meals!
Message Edité par Conseils le 07-13-2006 09:17 PM

PC parallel port access with XP

I recently got In Port and Out Port working on XP.
I searched the ni site for AccessHW. The CVI Run Time Engine has to be
version 5.510 or earlier. I checked the version number of one file, i.e.
cvirte.dll to verify.
I directed the installer to install accesshw to the directory where the new
In Port and Out Port and the rest of the new parallel port .vis were going
to be, i.e. Labview\Labview 6\vi.lib\platform.
I downloaded parallel.zip from ni.com and moved the parallelnt.llb file to
this same directory. Parallelnt.llb has a number of parallel port vis, not
just replacements for In Port and Out Port. I replaced the In Port.vi and
Out Port.vis in the diagrams I was trying to make work with the new .vis.
So, on this XP machine, with
a monitor program, parmon.exe, running to
display the bits on the parallel port, Labview can be seen to be using the
new parallel port .vis, and, bits on the port are changing.

I wonder if there's a reason why there's a javax.comm 3 series for *nix, but not for windows. Hmmm.

Is VISA Write VI / Out Port (need AccessHW) better for writing to parallel port?

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