Printer Port use as Input/Output

[Moe2]

Hello everybody,

I'm new in this forum, therefore I could need some help with a small problem.
I want to connect a measuring device (DIO) with the laboratory PC by using the LPT-Port.

By using the VISA write VI (http://digital.ni.com/public.nsf/allkb/B937AC4D8664E37886257206000551CB) (method 1) it works quite well.

But I got a little problem with the signal input to my Labview-PC.
I tryed to use a voltage source 5V with max 10 mA to set single channels (~10µs rising edge).
I checked channel 10,11,12,13,15 with the corrsponding ground connection (ref. to http://digital.ni.com/public.nsf/allkb/B937AC4D8664E37886257206000551CB TABLE1).

I've read that the input to PC via LPT works only with those channels.
Therefore I'm working only with "In Put / Out Put.VI" not with the Visa-Protocoll.(?!?)

Can someone lend me a helping hand or give me a small hint? Is it possible to use these channels for input without using Visa-protocoll?
(or an other method)

Aquisition:
PC->LPT->Device
4 channels->
4 channels<-

all digital
rising time of ~1ms is enough [fast is better ;-)]
(don't want to buy add. equipment, because it's my for my thesis)

[PhilipDeppe]

No,

thats not possible. You can only use your LPT port with the VISA protocol.

Cheers,

Philip

[H_SH]

Hi,

1) In 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.

2) Using "In Port.VI" and "Out Port.VI" , you can play very well with parallel port.

3) As per your requirements, 4 channel is to read and four channel is to write. So you can use Pin Number 2 to 9 as DIO operation.

Please reply with further query if you have in that acqusition system design..

Thanks

- HS

[smercurio_fc]

What exactly are you trying to measure? The parallel port is not a substitute for a real digital I/O device. When you said you have a voltage source of 5V with 10mA, are you actually connecting this directly to the parallel port? Have you checked the specs for the motherboard to make sure the parallel port is +5V tolerant? Recent parallel ports (if they actually exist on motherboards) are 3V, not 5V. Have you checked to make sure you're not exceeding the current limit of the parallel port? You may need to put a limiting resistor, else you will damage your motherboard.

[Mow]

Thanks for the response,
here is the employed student by Moe2 for the BA thesis. Now i got my own account.
The motherboard and the LPT-port still works fine on my laptop 😛
I tryed to simulate the communication with TTL-logic. Therefore I tryed to simulate the high and low level of my devices in both directions.
Like i said it worked fine with the digital output solution of the link. I recognised a voltage of about 3,3V at several channels with my measurment device. I though i could use 8 channels for output signals at one LPT port, but that doesn't matters anymore.

@phips: So for sure it is possible for the Output direction like H S said.

@smercurio_fc: Then i tryed to get a reaction of my labtop when i give a high-input, on a channel with my voltage source (5v about 10mA).
That means i want to simulate a high at the end of the LPT cabel and see a reaction on my labview prog depending on he channel i use.
I tryed to make it work well several times. But it did not...

We splitt the single strands of a normal printercabel --> See the Attachment for the understanding.

Thats why we decided to buy a NI USB-BOX 6501. I hope it becomes more easier to communicate with my devices.
Both devices i want to communcate with are steppingmotors with different parameters i need to controll or read.
At the end i should set these parameters true or false--> TTL ( normaly 5 V).
I dont wanna go into detail so far.
Thanks for your ideas and time u spend on my topic.
I got no solution for my problem but i think this topic could be closed.

Best Regards

[golubovski]

Hello,

I am just trying to play with outputting via the LPT port (ECP, 0x378) by using LV Outport.VI but cannot see any pulse on my oscilloscope...?!? What could be wrong, DeviceManager says LPT is working properly and there are no confilicts.

Thanks in advance,

[Coq_Rouge]

Please remember it is almost better to start a new thread than hi-jacking other threads. It can be very confusing to help in a hi-jacked thread. Reread this link http://digital.ni.com/public.nsf/allkb/B937AC4D8664E37886257206000551CB You have force some of the pins to GND.

[golubovski]

CR,

Sorry for hi-jacking but when one starts identical thread he is than reminded of the existance of the "original" one. Anyway, I am using OUTPORT.VI so no GND required for the BUSY and PAPER pins. Any other ideas?

Thanks in advance,