Hand Held Products SCANTEAM 2070, System Manual

Page: 78 / 232

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Auxiliary Port Input Communications
Protocol Selection
This selection programs the Auxiliary Port for the protocol required by the input
device to the Auxiliary Port. The protocol is a set of rules concerning the
exchange of data between serially communicating devices. The Auxiliary Port
supports Record, Burst, and ACK/NAK protocols when receiving data from an
RS-232 device.
When the Aux Port is being used as an input, data packets can be sent from the
peripheral to the Aux Port in two different forms (See "Data Character
Selection" on page 3-17).
• Record -- a single string of data that is to be sent to the host system.
• Block -- several strings of data that are to be appended together within the
base and sent to the host system as a single message.
The programmer should determine which of the four selections below best meets
the requirements of the peripheral.
• Record -- used when the transmitting peripheral is sending messages
when no confirmation of receipt is required.
• Record ACK/NAK -- same as Record, however the base responds to the
peripheral upon receipt of the message. The <ACK> (acknowledge)
character (ASCII 06 hex) is sent to the peripheral to acknowledge that a
<NAK> (non-acknowledge) character (ASCII 15 hex) is sent when the
message is not received correctly.
• Block ACK/NAK -- same as Record ACK/NAK, but the <ACK> or <NAK>
is issued upon completion of the block message.
• Burst -- used when XON/XOFF software flow control is required by the
transmitting peripheral.
*Record
Burst
Record ACK/NAK
Block ACK/NAK