Thanks for contacting Plugable support, I’ll be happy to help. You won’t be able to use LPT ports (parallel ports) since this is a serial connection rather than parallel.
I found instructions below on how to configure Seiko printers at: http://www.siibusinessproducts.com/us…
Q: How do I set up an SLP to print by serial? A: Do the following:
From within the Start Menu -> Control Panel -> Printers & Faxes
Double click “Add Printer”
Select a serial port. Usually COM1. (It may be COM2 through 4 if you have more than one serial port on your machine.) Push Next.
Turn off the “Automatically detect Plug and Play” checkbox.
Scroll to the end of the Manufacturer list and select “SII”.
Select your printer model from the “Printers” list. Push Next.
Keep existing driver. Push Next.
Give the printer a name. Push Next.
OPTIONAL: If you want to use the printer instance to print by SLP, turn sharing on for the printer. Push Next.
OPTIONAL: Enter location and comment.
Do NOT print a test page. Push Next. (Test pages are for legal paper and don’t work right for small labels.)
After the new printer appears in Printers & Faxes, right click the printer and select the “Properties”.
Click the “Ports” tab.
Select the COM port you chose in step 3.
Push “Configure Port” and change the settings as specified below:
SLP 440 or SLP 450: 38,400 Bits per second
SLP 410 SLP 420, SLP 430: 57,600 Bits per second
For all printers:
Stop bits: 1
Flow control: Hardware
If you change the speed settings, BE SURE to check other properties as well. Windows will sometimes reset them without warning.
Try to print from Notepad. If serial printing does not work, verify all of the settings above, especially the settings in step 15. Otherwise, you could have a bad cable, serial port, or printer.
I hope this helps, but please let us know if you’ve any other questions.