Specifications

3-4

3.2 USB INTERFACE SPECIFICATIONS

(1) General specifications

Item Specification

USB Version Ver 2.0 conformity

USB Printing class specification 1.1

Communication speed Full speed（12 Mbps）

Communication protocol Bulk transfer

(2) Pin assignment

Pin No. Name I/O Function

1 Vbus - USB power supply

2 D- I/O USB data signal

3 D+ I/O USB data signal

4 N.C. - No connection

5 GND - GND

(3) Connector

Mini B type

(4) Data reception

USB data reception uses a bulk-out transfer method.

The data are received even during the printing operation, and when the data accumulate in the input

buffer by the amount of input buffer + 2 packets, the NAK response continues until amount of the input

buffer becomes 129 bytes or more.

The number of bytes that can be received with one packet is maximum 64 bytes. When an error

occurs, the NAK response continues until the error is cleared after receiving data of 2 packets.

For the operation when an error occurs, the setting is changed by Busy Output When Error Occurs at

function setting.

(5) Data transmission

USB data transmission uses a bulk-in transfer method.

The response data are stored temporarily in the transmission buffer, and a response is made to the

bulk-in packet request from the host device. If no transmission data exist, the zero length data is

returned when the bulk-in request is received. The number of bytes that can be transmitted with one

packet is maximum 64 bytes.

(NOTE) Be aware that if the transmission buffer becomes full, the printer does not print

until the buffer is available.