Communications
FST 9000
Programmer’s Guide
100-14362
Rev A
Page 249
Appendix B: USB Printer Class Specification
The USB interface conforms to USB Printer class standard published by the USB
standards organization Version 1.1 dated January 2000.
The EPIC 3000 Printer will appear to the host system as a USB class 7 device.
There are 3 class specific requests that may be made to the printer after enumeration.
Label
bmRequest
Type
bRequest
wValue
wIndex
wLength
Data
GET_DEVICE_ID
10100001B
0
Config
Index
Interface &
Alternate
Setting
Length
Maximum
1284
Device ID
String
GET_PORT_STATUS
10100001B
1
Zero
Interface
1
BYTE
SOFT_RESET
00100001B
2
Zero
Interface
Zero
[None]
GET_DEVICE_ID (bRequest = 0)
This class-specific request returns a device ID string that is compatible with IEEE 1284.
See IEEE 1284 for syntax and formatting information. The wValue field is used to specify
a zero-based configuration index. The high-byte of the wIndex field is used to specify the
zero-based interface index. The low-byte of the wIndex field is used to specify the zero-
based alternate setting. The device ID string is returned in the following format:
Offset
Type
Description
0...n-1
Data
IEEE 1284 device ID string (including length in the first two bytes in big
endian format).
GET_PORT_STATUS (bRequest = 1)
This class-
specific request returns the printer’s current status, in a format which is
compatible with the status register of a standard PC parallel port. The following table
defines the data returned.
Bit(s)
Field
Description
7 .. 6
Reserved
Reserved for future use; device shall return these bits reset to zero.
5
Paper
Empty
1 = Paper Empty, 0 = Paper Not Empty
4
Select
1 = Selected, 0 = Not Selected
3
Not Error
1 = No Error, 0 = Error
2 .. 0
Reserved
Reserved for future use; device shall return these bits reset to zero.
