39
Software Handshaking
This parameter offers control of the data transmission process in addition to, or
instead of, that offered by hardware handshaking. There are five options.
If Software Handshaking and Hardware Handshaking are both enabled,
Hardware Handshaking takes precedence.
None: When this option is selected, data is transmitted immediately.
No response is expected from host.
ACK/NAK: When this option is selected, after transmitting data, the
decoder expects either an ACK or NAK response from the host.
When a NAK is received, the decoder transmits the same data
again and waits for either an ACK or NAK. After three unsuccessful
attempts to send data when NAKs are received, the decoder issues
an error indication and discards the data.
The decoder waits up to the programmable Host Serial Response
Time-out to receive an ACK or NAK. If the decoder does not get a
response in this time, it issues an error indication and discards the
data. There are no retries when a time-out occurs.
ENQ: When this option is selected, the decoder waits for an ENQ
character from the host before transmitting data. If an ENQ is not
received within the Host Serial Response Time-out, the decoder
issues an error indication and discards the data. The host must
transmit an ENQ character at least every Host Serial Response
Time-out to prevent transmission errors.
ACK/NAK with ENQ: This combines the two previous options. For
re-transmissions of data, due to a NAK from the host, an additional
ENQ is not required.
• XON/XOFF: An XOFF character turns the decoder
transmission off until the decoder receives an XON character.
There are two situations for XON/XOFF:
XOFF is received before the decoder has data to send. When the
decoder has data to send, it waits up to Host Serial Response
Time-out for an XON character before transmission. If the XON is
not received within this time, the decoder issues an error indication
and discards the data.
XOFF is received during a transmission. Data transmission then
stops after sending the current byte. When the decoder receives an
XON character, it sends the rest of the data message. The decoder
waits indefinitely for the XON.
Summary of Contents for Z-3152 Series
Page 1: ...1 Settings and Programming For 2D Image Scanners...
Page 36: ...33 Baud Rate 9600 Baud Rate 19 200 Baud Rate 38 400 Baud Rate 57 600 Baud Rate 115 200...
Page 43: ...40 None ACK NAK ENQ ACK NAK with ENQ XON XOFF...
Page 164: ...161 Appendix C Sample Bar Codes Code 39 123ABC UPC EAN UPC A 100 EAN 13 100...
Page 166: ...163 Data Matrix Maxicode...
Page 168: ...165 8 9 Cancel To correct an error or change a selection scan the bar code below Cancel...