Making a PC emulate a printer

E

Thread Starter

ekeil

I have a device that has only a standard LPT port which is designed to be cabled directly to a printer for status message printing. I am trying to get it connected to a PC so I can capture the messages and not bother printing them.

So far I've tried a Parallel -> Serial Converter and with a serial port monitor I 'see' the data coming across, but when I try a program like HyperTerm to capture it, I can't see anything.

What I was really trying for was a program that would receive data on the LPT port of my PC (maybe with a "laplink" or "null modem" cable between the device and the LPT port of the PC)?

Any help/ideas would be appreciated!
 
I might suggest that you contact a vendor of software for exactly what you are doing. "Machine Automation Inc.", has applications for exactly what you are trying to make. Very reasonably priced. www.machineautomation.org

Cheers.
 
R

Robert Scott

The parallel port is not symmetric. The PC end of a parallel port connection cannot be made to behave like the printer end. It does not have the hardware that latches data on a strobe input like a printer does. Your parallel to serial converter idea is the best bet because it is designed to emulate a printer, and a PC is perfectly capable of receiving the serial data. You just need to work out the details with hyper terminal or some other terminal emulation software, or maybe write a custom program to receive the data and process it.

Robert Scott
Real-Time Specialties
Embedded Systems Consulting


 
The LPTCAP adapter works well, but the software in the package works only in DOS; there's no windows version; maybe someone who is an assembler genius can port the software to windows.
 
I wrote a Visual Basic Program for capturing from LPTCAP-Adapter using inpout.dll from Logix4u
for reading/writing from LPT-Port. It works well, but my language is German, and so is the Program menu. I can send you the Setup-Package, if you are interested.
 
K

Keith Leitch

Hi,

I'm interested in your program. Can you send it to me, too? I want to capture the LPT-Port out of an Emergency Alert System (EAS) used in the US.

Thanks - Keith
 
If you are able to convert signal to serial, then search for "Advanced Serial Data Logger" at http://www.aggsoft.com. It can capture everything that com in and/or out of a PC serial port, it can automaticaly make daily text files with received data, it can run as a service. You can download a demo version, try it and buy the license later (standard version for about 60$ USD). We have been using it for 6 month, never failed...
 
I have a dos based program that runs only under win 98. (Also needs editing config.sys file under system root.) I used microsoft's virtual pc to run 98 on newer system, and software works fine here. Problem is that i need port for printing and my new printer is USB. Neither do i have printer drivers for 98, nor could i get usb working on 98 virtual machine. LTP works fine on virtual PC. Is there any way i can make a PC on network emulate as an old printer and use usb printer THROUGH it from virtual machine? I want to use usb laser printers instead of old dot matrix printer.

Or can i make this program run on win xp?
PS : no support from software vendor is available.
I tried compatibility mode and all, but doesn't work. If it works, it prints slowly, (could be the difference - dots and characters )

> You can download a Windows version for
> capturing from LPTCAP from
> http://www.englersteritech.at/LPTCAP HTML/DownloadAREA/LPTCAPDownloadDEU.htm
 
S
Run "NET USE LPT1: \\laptopname\printername /persistent:yes" on the host machine (laptop). Then you can configure Virtual PC to use that port as the LPT1 port of the VM, and you'll then have a parallel port in the virtual machine connected to your USB printer. If you then print from your app to that port, it might work. You should probably be configured for a generic text mode printer or as close to it as you can get.
 
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