LabVIEW
Parrallel port XP performance
Hello,
I am developing an application which is the software for a logical state analizer. (the communication with the analizer is based on the parralel port) To make this post as concrete and short as possible.
I have developed my application in LV 6.1 and used the Access HW library in order to be able to communicate throught the LPT port under windows XP.
My device works in a way that it fills internal memory cells with data which I than aquire though parralel port. I have to make approx 32k x 8 operations on the out port and the same amount of infort to get the measured data downloaded.
When I run my application on windows 98 machines the data acqusition takes about 21 seconds ( PII 300 MHz 256 RAM machines , in the lab), When I run the same application on my PC ( P41,7 512 RAM ) it takes a staggering 50 on some XP PC's I even had a 70 sec. data download.
Are there any suggestions ... I can post my data Acq module gladly if some one would be willing to take a look at it.
Any quick ideas on where I could have gone wrong ??? ... I myself lack the experience ;/ (I am a student hence I am a relatively unexperienced developer)
Regards,
Maciej
I am developing an application which is the software for a logical state analizer. (the communication with the analizer is based on the parralel port) To make this post as concrete and short as possible.
I have developed my application in LV 6.1 and used the Access HW library in order to be able to communicate throught the LPT port under windows XP.
My device works in a way that it fills internal memory cells with data which I than aquire though parralel port. I have to make approx 32k x 8 operations on the out port and the same amount of infort to get the measured data downloaded.
When I run my application on windows 98 machines the data acqusition takes about 21 seconds ( PII 300 MHz 256 RAM machines , in the lab), When I run the same application on my PC ( P41,7 512 RAM ) it takes a staggering 50 on some XP PC's I even had a 70 sec. data download.
Are there any suggestions ... I can post my data Acq module gladly if some one would be willing to take a look at it.
Any quick ideas on where I could have gone wrong ??? ... I myself lack the experience ;/ (I am a student hence I am a relatively unexperienced developer)
Regards,
Maciej
Werner,
Thank you very much for the info. This application is my diploma work. And hence I will not use an internal PCI Card ( The universyty has low budget as it is).I shall keep to Access HW as I would like the software I have made to work on every workstation .Currently my University uses win98 in the Lab the analizer is desitignated to be used in, but if they decide to upgrade to XP next year I would not like my software to become copletely useless ... too bad it will take 2x more time to make the data acq but the device will sitll be somewhat usefull).
And for the record I was developing the app mostly on my comuter which has the XP system installed, so that is why I used Access HW in the first place ;]
I was thinking perhaps of maybe using an external library (not one made by National Instruments) to comunicate with the parallel port , perhaps use a dll written in another language ... , But since NI wrote the Access HW I guess they knew what they were doin'. Perhaps this is an XP fault and I have nothing to say here.
Thank You very much for the feedback ... Looks like my app will stay the way it is than. Unless some one else jumps out with a brilliant, simple and ellegant solution ;]
Best Regards,
Maciej
Thank you very much for the info. This application is my diploma work. And hence I will not use an internal PCI Card ( The universyty has low budget as it is).I shall keep to Access HW as I would like the software I have made to work on every workstation .Currently my University uses win98 in the Lab the analizer is desitignated to be used in, but if they decide to upgrade to XP next year I would not like my software to become copletely useless ... too bad it will take 2x more time to make the data acq but the device will sitll be somewhat usefull).
And for the record I was developing the app mostly on my comuter which has the XP system installed, so that is why I used Access HW in the first place ;]
I was thinking perhaps of maybe using an external library (not one made by National Instruments) to comunicate with the parallel port , perhaps use a dll written in another language ... , But since NI wrote the Access HW I guess they knew what they were doin'. Perhaps this is an XP fault and I have nothing to say here.
Thank You very much for the feedback ... Looks like my app will stay the way it is than. Unless some one else jumps out with a brilliant, simple and ellegant solution ;]
Best Regards,
Maciej
Shane,
As far as I am aware using VISA with the parralel port enables you only to commit write operations.
from the NI support :
"Windows environment we can output data to the parallel port using the same VISA VIs that we would use for normal serial communication. However, the Windows API does not have built in support for input operations"
I however need access to all three LPT registers Data, Status and Control. So using VISA is totally out of the question.
Besides using the outport and inport is a more low level approach and I would expect it to have far better performance, than having to cast from numeric value to string in order to use the VISA.vi about 256 k times in my application each time I download the measured data.
Thank you for replying,
Best regards Maciej
As far as I am aware using VISA with the parralel port enables you only to commit write operations.
from the NI support :
"Windows environment we can output data to the parallel port using the same VISA VIs that we would use for normal serial communication. However, the Windows API does not have built in support for input operations"
I however need access to all three LPT registers Data, Status and Control. So using VISA is totally out of the question.
Besides using the outport and inport is a more low level approach and I would expect it to have far better performance, than having to cast from numeric value to string in order to use the VISA.vi about 256 k times in my application each time I download the measured data.
Thank you for replying,
Best regards Maciej
Hello,
Werner and anyone else interested here is my code. The way it works is ... well ;] not wery simple to explain if you want more info on why and where I can e-mail the schematic...
The top level VI is called ACQISITION.vi
Regards,
Maciej
Werner and anyone else interested here is my code. The way it works is ... well ;] not wery simple to explain if you want more info on why and where I can e-mail the schematic...
The top level VI is called ACQISITION.vi
Regards,
Maciej
JLS,
Thanks for the post. Unfortunately none of the threads You have posted addreses my problem :(.I have no problems with communicating with my device actually it works the way I want it to. The problem is that under the XP operating system I suffer a lowered performance compared to win98 systems as I have written in the OP.
And unfortunately I cannot use VISA as it does not support input operations for LPT.
Regards,
Maciej
Thanks for the post. Unfortunately none of the threads You have posted addreses my problem :(.I have no problems with communicating with my device actually it works the way I want it to. The problem is that under the XP operating system I suffer a lowered performance compared to win98 systems as I have written in the OP.
And unfortunately I cannot use VISA as it does not support input operations for LPT.
Regards,
Maciej
