
5. EXPANSION PROTOCOL A B-63322EN-1/01
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5.3
MONITOR PACKET FORMAT
The monitor packets transmitted from the remote buffer to the host
computer are shown as below. All packets have the fixed length
consisting of 5 bytes.
1) Stop request
The stop request is transmitted to the host computer by the
remote buffer when resetting the NC and stopping data reception
by an alarm.
Transmit the end packet (the NC is dummy) after transmitting
the packet which is currently being transmitted and move to the
normal protocol A mode when this packet is received by the host
computer.
If the end packet was being transmitted when the CAN packet
was received, the end packet need not be retransmitted in
response to CAN.
Transmit the end packet even in the DC3 reception status.
2) Retransmission request
When a check sum error is detected in the received packet, the
retransmission request corresponding to the packet is transmitted
by the remote buffer.
The host computer should perform retransmission from the
corresponding packet immediately after ending the transmission
of packet which is currently being transmitted when it receives
this packet.
CAN
( 18h )
Meaningless
(20h )
End code
( 0Dh )
Checksum
( 2 b y t e )
NAK
( 15h )
Packet No.
(1 byte)
Checksum
( 2 b y t e )
End Code
(0Dh )