Microscan Quadrus MINI, User Manual, Page: 382 / 424

A-20
Quadrus MINI Imager User’s Manual
Communications Protocol
Polling Mode Data Flow Examples
Setup 1
Transfer 1
Transfer 2
Starting with a ‘RES’ ensures a clean transaction, without “leftovers” from the previous
transaction.
Error Condition 1
Address 0x01 (translates to) Poll Req @ ‘0x1C’, Unit Select @ ‘0x1D’
RES 0x04
REQ 0x05
STX 0x02
ETX 0x03
ACK 0x06
NAK 0x15
LRC disabled
HOST_TX ‘RES’ ‘0x1D’ ‘REQ’ (Select Unit 1 to receive data)
IMAGER_TX ‘0x1D’ ‘ACK’ (Unit responds with its address)
HOST_TX ‘STX’ <T> ‘ETX’
IMAGER_TX ‘0x1D’ ‘ACK’ (Unit responds with its address)
HOST_TX ‘RES’ (Terminate Transfer 2)
HOST_TX ‘RES’ ‘0x1C’ ‘REQ’ (Poll Unit 1 for data)
IMAGER_TX ‘0x1C’ ‘STX’ <T/00000> ‘ETX’
HOST_TX ‘ACK’
IMAGER_TX ‘RES’ (Terminate Transfer 1)
HOST_TX ‘RES’ ‘0x1C’ ‘REQ’ (Poll Unit 1 for data)
IMAGER_TX ‘0x1C’ ‘STX’ <T/00000> ‘ETX’
HOST_TX ‘
Nothing
’ (Host should ‘ACK’ here)
timeout reached...
IMAGER_TX ‘REQ’ (Unit requests an ‘ACK’ again)
timeout reached...
IMAGER_TX ‘REQ’ (Unit requests an ‘ACK’ again)
timeout reached...
IMAGER_TX ‘REQ’ (Unit requests an ‘ACK’ again)
timeout reached...
IMAGER_TX ‘RES’ (Terminate Transfer 1, data is flushed)