HP Retail Integrated 2x Point of Sale POS Peripherals Configuration Guide - Page 82

6.4.5 COMM CLASS Mode If the correct boot and flash firmware level are present on the printer (see table below) the printer can be put into COMM CLASS. When the printer is in COMM CLASS mode a virtual COM port is assigned to the printer USB interface for application that only communicate to the printer via serial port. One can look in Windows Device Manager  PORTS to determine the virtual com port that Windows assigned to the virtual printer COM port. Steps to change COMM class are covered in USB MODE SELECTOR section of the document). Note: The COMM CLASS option is available only on the A799 powered USB model and A776 printer. The following are minimum version of the firmware that supports the COMM CLASS option: Firmware Version A776 A799 Boot Firmware Version 1.25 1.06 Flash Firmware Version 2.00 1.08 Note: If the printer has later versions then what is listed in the above table, the printer firmware does not need to be downgraded to the version in the table. In order to obtain the firmware that is installed on the printer, perform the following steps when you are in front of the printer: 1. Open the printer cover that holds the thermal receipt paper. 2. Hold down the printer form feed button and close the printer cover. 3. Release the form feed button on the printer and a diagnostics printout will be printed. The following are examples of the diagnostics printout: HP Single Station Printer (A799) HP Hybrid Thermal Printer (A776) Page 82 of 545