Software Handshaking - Symbol Cyclone M2000 Series Product Reference Manual

Software Handshaking

This parameter offers control of the data transmission process. It may be used instead of,
but not in conjunction with, hardware handshaking. ACK/NAK handshaking may be
combined with ENQ handshaking.
• No Software Handshaking: Data is transmitted immediately.
• ACK/NAK Only: When this option is selected, after transmitting data, the scanner
expects either an ACK or NAK response from the host. When a NAK is received,
the scanner 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
scanner issues an error indication and discards the data.
• ENQ Only: When this option is selected, the scanner waits for an ENQ character
from the host before transmitting data. If an ENQ is not received within 2 seconds,
the scanner issues an error indication and discards the data. The host must
transmit an ENQ character at least every 2 seconds to prevent transmission errors.
• ACK/NAK with ENQ: This combines the two previous handshaking options.
• XON/XOFF: An XOFF character turns the scanner transmission off until the
scanner receives an XON character. There are two situations for XON/XOFF:
• XOFF is received before the scanner has data to send. When the scanner has
data to send, it then waits for an XON character before transmission. The
scanner waits up to 2 seconds to receive the XON. If the XON is not received
within this time, the scanner 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 scanner receives an XON character, it
sends the rest of the data message. The scanner waits indefinitely for the XON.
Select the type of RS-232C software handshaking protocol.
Parameter Menus
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