KoamTac KDC200 KDC250, Руководство по программированию

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Packet Data
KDC200 supports user selectable two data formats:
z
Barcode only and
z
Packet data.
By default, KDC200 sends data with Barcode. If KDC200 is configured to send Barcode only data, KDC200
doesn’t do handshake with host application. However, if KDC200 is configured to send packet data, KDC200
needs to do handshake with host application to make sure that HOST receives read barcode correctly. There are
two cases of sending packet data to host:
z
synchronization mode and
z
Wedge mode
HOST response to KDC200 after receiving data command
KDC200 expects the HOST to send two kinds of response to KDC200 once HOST received packet data from
KDC200:
z
Success response or
z
Failure response.
HOST is required to send a success response if it receives a packet data successfully by sending a character ‘@’.
If HOST detected an error while receiving a packet data from KDC200, HOST should send a failure response to
KDC200 by sending a character ‘!’.
Wedge mode
If KDC200 read a barcode and configured to send packet data, KDC200 waits for 1 second to get a response
from HOST after sending a read barcode data to HOST. KDC200 goes to ready mode upon receiving either
success or failure response. KDC200 goes to ready mode if there is no response from Host in 1 second. KDC200
doesn’t resend the data either receiving failure response or 1 second time out. The following is detail steps
between HOST and KDC200.
a) HOST configures KDC200 to send packet data
b) User presses SCAN button
c) KDC200 reads barcode data
d) If reading is success, KDC200 sends a packet data leading a character 0x03 and ending with
checksum.
e) KDC200 goes to waiting state.
f) HOST receives a packet data from KDC200.
g) HOST checks if it receives a packet data without error.
h) HOST sends a success response by sending a character ‘@’ to KDC200 or a failure response by
sending a character ‘!’.