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Infinite Peripherals, Inc.
Page 3
www.ipcprint.com
PP-55 Resident Command Set Version 1.01
Communication Modes
2.
Protocol description
PACKET FORMAT
-------------------
PORT COMMAND/STATUS LENHI LENLO ...DATA...
PORT:
bit 0..6 port number (device type)
bit 7: response, 0:send data, 1:answer
COMMAND: (if response bit is 0)
0: open port
1: close port
2: send data
3: request data
4..255: application specific
STATUS:
(if response bit is 1)
bit 0: error
0:
No
error
1:
error
occurred
bit 1: confirm
0:
ACK
1:
NAK
bit 2: channel or command error
0: channel and command OK
1: channel or command not supported
bit 3..7: application specific
LEN:
length of data
The maximum packet length is 2048 bytes. The answer differs from the
command by bit 7 (MSB) in the port number. If bit 7 is 0 then it is a command,
if it is 1 then it is a response. Bit 0 in the status byte shows if there was an
error accepting or processing the data block. If this bit is 1 the other bits show
the type of the error.
The printer never issues a transmission by itself. It always responds as an
answer to a command. The communication goes like this:
PDA – command, printer – answer; PDA – command, printer – answer; etc.
