Dynamometer/MSDOS Printing

[RogueTech]

I have a unique system I have been tasked with maintaining and I am hoping the RetroPrinter device will be just what I need.
It's an old Water Brake Dynamometer from the 1990s used for testing performance metrics of stock car racing engines. The sensor leads are plugged into a computer tower running MS-DOS which runs a proprietary testing software. Once testing is complete, the data is then printed. The system is designed with a centronics LPT port and no USB printing support.
We have tried multiple LPT based printers (all used/refurbished), and only the HP DeskJet 5650 works correctly. I purchased a device that converts LPT to USB, but found out after the fact that it merely converts the signal, the printer still has to support LPT printing, I am guessing via PCL3. Unfortunately with zero documentation I am uncertain which printing standard(s) the MSDOS based software utilizes. Unfortunately the company that made this Dynamometer/MSDOS Software was bought out decades ago, all documentation was destroyed and the product line terminated. Due to this I am really stabbing in the dark to find a printing solution. HP DJ 5650s havent been manufactured in a LONG time and the ones I can find are all used/refurbished, cost upwards of $500 and only have their USB port tested, not LPT. We have already purchased several old printers, 1 of which didn't work, 2 of which arrived in a broken unusable state, basically throwing our money down the drain. We really want to find a solution that allows us to use a modern printer, both to reduce cost involved and not having to worry about buying/using old printers.

Based on this information, do you think the RetroPrinter would be the solution I need? If so I am willing to buy the full kit.

[RWAP]

Hi,

Thank you for your enquiry. Yes, the Retro-Printer should be more than able to cope with this scenario. We work to capture and convert various HP DeskJet printers - the reason the LPT to USB convertor probably did not work is probably because a DeskJet surrounds the PCL3 or PCL5 printer codes with printer job information.

The Retro-Printer software strips out this printer job information, so that the standard PCL convertors can work on the captured data.

Rich

[RogueTech]

Rich,

Thank you for the reply. Sounds like this will work for me. I will be picking up one of your kits shortly here. I will update this thread after I test it on the dynamometer system.

[RogueTech]

Hi,

Thank you for your enquiry. Yes, the Retro-Printer should be more than able to cope with this scenario. We work to capture and convert various HP DeskJet printers - the reason the LPT to USB convertor probably did not work is probably because a DeskJet surrounds the PCL3 or PCL5 printer codes with printer job information.

The Retro-Printer software strips out this printer job information, so that the standard PCL convertors can work on the captured data.

Rich

Hey Rich, I did end up ordering the RPM v4 full kit and have hit a roadblock. Upon connecting and powering up the RPi, I was NOT able to immediately use CUPS as the setup instructions say to. Tried two web browsers, both would return a "connection refused" error. Being new to CUPS, I did some research. First I checked the cupsd.conf file... which was blank. So I deleted the blank .conf file and then I used "sudo dpkg-reconfigure cups" to generate a new file. Then using nano I found by default the cupsd.conf file does NOT allow access to the CUPS webserver. I was finally able to configure it to allow access.

Now here's where it gets confusing. In CUPS web portal, I was able to get my printer (HP OffficeJet 8025e) installed. However, when looking for new printers, it shows 4 variations of the printer (printer, printer+USB, printer+fax, printer+fax+usb). The printer+USB one seemed to install itself as it was already in the list of printers. However, when getting to the screen where I pick a driver, it gives me 6 choices: 8000 series PS (recommended), then a "driverless" variant, then 4 identical entries that use drivers (with no indication of how they are different).

Long story short: I have tried every possible combination printers and drivers and nothing happens. Added printers, removed printers, configured printers over and over. Despite this, the CUPS web portal does not even register incoming print jobs, that list was always blank even after trying to print a dozen plus times. I went through your setup documentation, checked all the various configs in /root/config/ to make sure they were setup correctly and they were. Just to make sure, I used the existing MS-DOS computer/LPT cable/HP 5650 and that combo prints fine. Definitely a signal coming through the LPT. I spent about 4 hours trying to get it to work with no luck. I am probably missing something so I figured I would reach out to you in search of answers.

[RWAP]

I shall have to look at cups setup again - it always worked here!

If no print jobs are being created - can you print a test page and is the printer set as the default?

If yes to both then send me the raw files - if they are not correct then the pdf will not be generated which is needed for printing!
Rich

[RogueTech]

Thank you for responding. In regards to CUPS I noticed a person posted in another thread that they too ended up with a blank cupsd.conf file so there may be an issue with the way you are deploying it or maybe just with CUPS itself.

I have NOT tried to run a test print and not sure how to set the printer as default in CUPS. I manually removed all but one printer from the list available, so I assumed it would be set as default. I will absolutely try a test print ASAP!

Where would I find the RAW files?

Also, I thought the PDF thing was merely a print-to-PDF converter. Is converting to PDF part of the LPT -> USB conversion?

[RWAP]

Yes, you have to manually set the default through cups console - select the printer use the admin tools drop down to set as server default.

We have to create an image of the printed page to send to the new printer, si we create it as a PDF.

raw files are normally in /home/pi/data/raw

[RogueTech]

Yes, you have to manually set the default through cups console - select the printer use the admin tools drop down to set as server default.

We have to create an image of the printed page to send to the new printer, si we create it as a PDF.

raw files are normally in /home/pi/data/raw

I followed your advice and went back to square one. Printer list was cleaned up and then a single printer was installed. I ran a test print as you suggested, and it did indeed print out a debian test page. Unfortunately I can not get back down to shop where the DOS machine and Dynanometer are until later this coming week. I will again try it out down there and if nothing happens, will grab the .raw files and share them with you.

[RogueTech]

Yes, you have to manually set the default through cups console - select the printer use the admin tools drop down to set as server default.

We have to create an image of the printed page to send to the new printer, si we create it as a PDF.

raw files are normally in /home/pi/data/raw

Hello Rich,

It's been awhile but I am back at it with my MSDOS/Dynamometer printing project. It does appear that CUPS was in fact capturing the old MSDOS print information. I found 8x .raw files (/home/pi/data/raw) and 8x .pdf files (/home/pi/data/pdf) which corresponds with the 8 tests I performed. What was NOT happening is the raw and/or PDF being actually printed on my newer HP OfficeJet Pro 8025e. I guess don't have the proper software to access the .raw files, when opened in InfranViewer image viewer, just shows bands of colors. I am attaching raw #1 and pdf #1. The pdf shows how the print data needs to actually be printed. Any ideas at to what may be going wrong here? Also, CUPS shows 2 versions of the same printer for whatever reason. Do I need both? Is one correct and the other not? My OfficeJet Pro is connected to the RPi via USB.

• Queue Name Description Location Make and Model Status

• HP_OfficeJet_Pro_8020_series HP OfficeJet Pro 8020 series HP Officejet Pro 8020 Series, hpcups 3.22.10 Idle

• HP_OfficeJet_Pro_8020_series_ HP OfficeJet Pro 8020 series Local Printer HP OfficeJet Pro 8020 series, driverless, cups-filters 1.28.17 Idle

One additional question: I noticed that CUPS 3.0 has been released but I am using CUPS 2.4.2. Would it be beneficial to update to a 3.x version?

P.S.
Last year I had mentioned to you that by default CUPS no longer allows just any IP remote access, so usually the cupsd.conf had to be edited. I have since found a shortcut you may wish to pass on your customers. The following will allow ANY IP to access the web server.
sudo cupsctl --remote-any
sudo /etc/init.d/cups restart

[RWAP]

If it is not printing the created PDF then check the settings in /root/config/output_printer is yes and that you have assigned a printer in CUPS as the server default.

The PDF itself looks good to go.

It would be interesting to know what make the Dynamometer is so that we can add this as tested on our list of equipment.