Am having problem communication with the printer through the USB port.

If you have not yet solved this issue , advise if you are on a paralell cable or usb cable connection? If it is a paralell connection pull the cable out and check for a bent pin, if affirmative straighten it out with small thin head pliers. If usb check that the correct driver has been loaded on the virtual usb port. Good Luck Ed Pinero

go to your control panel & delete the printer, shut down & restart turn the printer on after restart see if the computer sees the printer if not try reinstalling if this doesn't work possibly the adaptor

send a test print from the driver.
check the connection configuration.
if connect with serial port (check seting from the port (THE SPEED HAVE TO BE THE SAME)
if connect with USB, if necessery, install the driver again and test.
if necessery flash the firmware and test (worst case scenario)
if can't comunicate and if using paralel port:
check if the fuse next to the paralel port is burn ( on the logic board.). replace it.
dont forget to unplug the power cable and the comunication cable.

Push the parallel end of the cable adapter onto the parallel port of the printer. ... Ensure that the clips for the parallel port and cable are in the locked positions. 3. Unplug the USB end of the cable from the USB port on the computer, and then reinsert it.
Also look here-
https://yourbusiness.azcentral.com/use-parallel-scanner-usb-7712.html

make sure you follow this step :
1. install driver USB to Paralel port (LPT1) before the cable connected to PC
2. After the driver installed, install the cable - and it supposed to be detected
3. the last think u have to do is install the scanner/printer driver

if it is not work, i guess the problem is on the USB to paralel adapter, or the driver not installed correctly

It will not work with any drivers if you do not have a parallel port. You can get a pci card that has parallel port on it for use with the zebra z4m.
below is a link for the card that cost only $9.99
http://www.gogocost.com/xcart/product.php?productid=275

You need to create an account here to find your drivers:
https://www.epsonexpert.com/login

And use that to find your drivers. Don't look through the main Epson site -- your printer's in a different category, for point of sale.

You are correct on your deduction.
It is the USB to Parrallel adpter. They are not reliable in the XP/Vista enviroment. I have run into this several times.

I’m happy to assist further over the phone at https://www.6ya.com/expert/joe_8b8c2cd6ce148309

If it's because your laptop does'nt have a paralell port you can use a Paralell to USB adapter cable.
Have a look on EBay.
http://search.ebay.com/parallel-to-usb-cable_W0QQ_trksidZm37QQfromZR40

You need to get a paralell to USB cable, like the one on the following link: http://catalog.belkin.com/IWCatProductPage.process?Product_Id=20651