Confirmation Handshaking - Allen-Bradley 1784-KTX Reference Manual

Confirmation Handshaking

Whenever the scanner services a host command, it places a confirmation
(which includes completion status of the command) into its confirmation
queue. Confirmations are removed from the queue and copied into the
confirmation buffer in the dual port as the confirmation buffer is processed
by the host. This diagram illustrates the handshaking for a confirmation
sequence. Notice the host may not initiate a confirmation sequence until
the
KTx
When the confirmation becomes non empty AND the
host has acknowledged the last confirmation, the KTx
copies a confirmation into the confirmation buffer.
Writes 02 (CONFIRMATION_INTERRUPT) in
int_status_to_host.
Causes a host interrupt by writing to the host
interrupt register of the ASIC.
On receipt of interrupt, copies the next confirmation into
the confirmation buffer (if a confirmation is available).
Writes 0 to int_status_from_host.
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variable in dual port has been cleared.
int_status_from_host
Chapter 3
Programming Overview
Host
Reads the confirmation from the confirmation buffer.
Writes 0 into the first byte of the confirmation buffer.
Writes 02h into int_status_from_host to indicate the
interrupt type is a CONFIRMATION_PROCESSED.
Writes 0 into int_status_to_host.
Interrupts the KTx by writing any value to
KTx register :801h, host_to_ktx_int_reg.
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