9560 Transaction Manager User's Manual - Intermec

Data Communications and Operating Options
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6. If the REQ is enabled, also enable the RES. When the REQ is enabled, the
reader waits for the timeout period to expire and then accepts the data. By
enabling the RES, the host sends the RES when it recognizes the response
(AFF) sent by the reader if the data was correctly received.
Buffering Received Data
The 9560 uses three different circular queues to hold received data.
20-byte queue Buffers all characters received. This queue serves as a buffer if
the data cannot be processed as fast as it is received. If XON/XOFF flow
control is enabled, the device transmits the XOFF character when the queue is
half full.
512-byte queue Buffers data characters only. When the data queue has 32 bytes
remaining, the reader sends the XOFF character to the host.
Packet queue Contains a pointer to the packet start position and a byte count.
This information is used to pass complete packets of successfully received
messages to the operating system. The packet queue holds up to 20 packets.
The device sends the XOFF character when the queue has 18 packets.
Communications Delays
While receiving data, the reader waits a specific time before sending an error
message. You can modify this time in Point-to-Point or User-Defined protocols.
Intercharacter delay The amount of time the reader waits before sending each
character to the host. This delay modifies the outgoing transmission rate only.
Use the intercharacter delay when communicating with a controller through
modems in full-duplex operation.
Timeout The amount of time the reader waits between receiving each character
before sending an error message. Also, it is the amount of time the reader waits
for an acknowledgment from the host before sending an error message.
Turnaround delay The amount of time the reader waits after receiving data
before sending a response to the host.
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