Microscan EZ Match, User Manual

Page: 393 / 431

EZ Match User’s Manual
A-23
Appendices
Error Condition 2
Error Condition 3
The protocol makes 3 retry attempts before data is flushed and transfer is aborted.
HOST_TX ‘RES’ ‘0x1C’ ‘REQ’ (Poll Unit 1 for data)
IMAGER_TX ‘0x1C’ ‘STX’ <T/00000> ‘ETX’ ‘LRC’
HOST_TX ‘ Nothing ’ (Host should ‘ACK’ here)
timeout reached...
IMAGER_TX ‘REQ’ (Unit requests an ‘ACK’ again)
HOST_TX ‘ NAK ’ (Host rejects data frame)
(Retry Event)
IMAGER_TX ‘0x1C’ ‘STX’ <T/00000> ‘ETX’ ‘LRC’ (Unit sends again)
HOST_TX ‘ACK’ (Host receives data)
IMAGER_TX ‘RES’ (Terminate Transfer 1)
HOST_TX ‘RES’ ‘0x1C’ ‘REQ’ (Poll Unit 1 for data)
IMAGER_TX ‘0x1C’ ‘STX’ <T/00000> ‘ETX’ ‘BAD LRC’
HOST_TX ‘NAK’ (Host rejects bad LRC data)
(Retry Event)
IMAGER_TX
‘0x1C’ ‘STX’ <T/00000> ‘ETX’ ‘GOOD LRC’ (Unit sends again)
HOST_TX ‘ACK’ (Host receives data)
IMAGER_TX ‘RES’ Terminate Transfer 1)