Hi.

I've read that PCI parallel port cards are more or less useless but printing..

I'm about to write an interface prog for controlling a preety old equipment which takes input by a parallel port, but from what I've heard other people before me failed. I suspect that it has to do with it.

IS this true? Should I search for a specific brand of PCI Parallel card or is there any other equipment I could use?

Thanks in advance.

 

parallel port considered legacy and killed off.
you can still get PCI card or usb to parallel converter.

people that have failed are those who wanted to apply what they learned under DOS 25 years ago and have hard time realizing that direct access to hardware has become obsolete with newer operating systems.

 

the parallel port is alive and well. Driven by sophisticated processors, it drives much of industry today.

 

it may depend on industry. i'm working in industry for over two decades. i've seen parallel port actually being used maybe twice, driving some old printer.

 

Parallel ports driven off a PCI bus are still pretty common in scientific and instrumentation. As far as 'is there any other equipment I could use?'
I haven't worked on a PLC yet that doesn't employ parallel ports.

 

interesting... you got me curious.
what PLCs did you use? do you have part numbers for any of LPT cards?

I have used few but never came across parallel port (which is not to say that they don't exist).
For example I work with:
Allen Bradley (PLC5, SLC, MicroLogix, FlexLogix, CompactLogix, ControlLogix)
Mitsubishi (A, AnS, QnA, QnS, Q, FX, FX1S, FX1N, FX2N, FX3U, Alpha etc.),
Omron (CS, CJ1M, CP,...)
Panasonic (FPX,FPe, FPsigma, FP0R...)
Siemens (S7-300, S7-400, S5...)
Automation Direct (DL105, DL205, Click...)
bunch of others using CoDeSyS (Bekhoff, Turck, BnR, ...)

 

Well take a PIC 13k50, add one 74hc595, there you go with a parallel port (for writing). If you want to read back, add a 74hc165 as well.

These 74hc chips are surprisingly fast.

All you need to program a 13k50 is a PICKIT3. You can really just mount it on a small PCB, add USB socket+ 12Mhz crystal, that's it. The USB stack is supplied from Microchip. Well it is for the 14k50, so you need to buy that chip, or you need to modify it.

Who really needs a hardware parallel port these days? Maybe people who are unable to use modern microcontrollers, but who need to deal with older equipment at the same time. I have understanding for the situation.

The test/scientific equipment maybe was expensive, very expensive, and still performs well.

So, what to do? Hire a professional embedded programmer to add a USB interface. It can be done in a matter of a few days, and even if you consider a fully professional implementation, won't cost more than a few 100 $.

There are even ready-made USB to RS232 adapter modules, PCBs, and chips. These don't need special software. Turning them into a parallel port is a matter of adding just a few 74HC chips. And these modules cost $10 to $15.

The serial RS232 port is still supported by Windows (and for C++).

 

well, after reading first 5 words, I can say with 100% confidence that you don't know what a PLC is... ;-)

http://en.wikipedia.org/wiki/Programmable_logic_controller

you would probably fall of the chair if you knew price for something like this:
http://upload.wikimedia.org/wikipedia/commons/2/25/BMA_Automation_Allen_Bradley_PLC_3.JPG

 

well, after reading first 5 words, I can say with 100% confidence that you don't know what a PLC is... ;-)

http://en.wikipedia.org/wiki/Programmable_logic_controller

you would probably fall of the chair if you knew price for something like this:
http://upload.wikimedia.org/wikipedia/commons/2/25/BMA_Automation_Allen_Bradley_PLC_3.JPG

It is not clear who introduced PLC here.
OP should specify the old equipment, if possible including the data rate, and/or if the data rate is required to be constant.

 

OP should specify the old equipment, if possible including the data rate, and/or if the data rate is required to be constant.

i can agree with that

 

the OP mentions 'printer' but only to discard that as consideration. Should we continue this conversation based on your assumption of 'LPT', or a generic 'byte/word wise' port.

 

I heard some usb → printer port, usb → rs232 will not working well, even won't work.

But the PCI to printer port didn't hear anything bad.

 

Controlling the parallel port is fast and reliable under dos or Win95/98.

After that Windows controls the ports via slow and clunky APIs.

If you are writing code to control the parallel port can you ensure your customer will use dos to run the software? Or are you happy to run the parallel port under windows and have it be slow and have big pauses?