101
6-4 SCI transactions notes
a) Flow control Option
ACK/NAK handshaking is selected by default. Changing this is not recommended as it causes some
communication problems (see 6-1) since ACK/NAK handshaking is the only indication that a message
was received and if it was received correctly. ACK/NAK is not used to respond to the unpacked decode
data whatever Flow control is set.
b) Number of Data Bits
All communication with the scanner must use eight bit data.
c) Response delay (see section
“
4-3 RS232 interface
”
)
The Response delay parameter determines how long to wait for a handshaking response before trying
again, or aborting any further attempts. Both the host and scanner should apply the same parameter
value during communication.
A temporary change may be made to the Response delay when the host takes longer to process an
ACK, or longer data string. Frequent permanent changes are not recommended due to the limited
write-cycles of flash memory.
d) Retries
When sending data, the host should resend twice after the initial send if the scanner does not respond
with an ACK or NAK (if ACK/ NAK handshaking is selected).
e) Baud Rate, Stop Bits, Parity, Response Time-out, ACK/NAK Handshake
If the serial parameters above are changed using PARAM_SEND, the ACK response to the
PARAM_SEND uses the previous values for these parameters. The new values then take effect for the
subsequent transaction.
f) Errors
The scanner generates a communication error when:
The time that scanner waits Host-character delay is time-out.
Failed to receive an ACK or NAK after initial transmit and two resends.
g) SCI Communication Notes
If handshaking is not used, messages should be spaced sufficiently apart, and the host must avoid
communicating with the scanner when the scanner is sending.
There is a permanent/temporary bit in the PARAM_SEND message. Temporary changes are lost
when power is removed from the scanner. Permanent changes are written to flash memory.
Frequent permanent changes are not recommended due to the limited write-cycles of flash memory.
Do not scan configuration barcodes and send parameters via SCI simultaneously.
Summary of Contents for FS580
Page 1: ...FS580 Industrial Fixed Laser Barcode Scanner User Manual Version FS580_UM_EN_V1 1 6...
Page 2: ......
Page 8: ...2 Figure 1 1 Pitch Skew and Roll...
Page 16: ...10 3 4 Scan angle Scan angle Narrow 40 5 Scan angle Wide 55 5 Figure 3 4 Scan angle...
Page 74: ...68 Testing barcode...
