User's Manual

Table Of Contents
MPI 6000 Multi-Protocol Reader System Guide
6-8
<cmd> = command, a word that specifies the
system command. See the command
sections for details.
<cmdSeqNum> = command sequence number, a byte
that specifies the command
sequence number of the message. See the software communication sequence number
controls section for details.
[<data>] = optional data payload
that varies in length from 0 to 65 bytes and is asso-
ciated
with each specific command. See the command sections for details.
<checksum> = checksum,
a byte that specifies the checksum of the
message.
Data Acknowledge Message
The MPI 6000 sends data acknowledge messages to the host after receiving command
request messages from the host.
The host sends data acknowledge messages to the MPI 6000 after receiving command
response messages, asynchronous resp
onse messages, software flow control messages
and unsolicited status messages from the MPI 6000. The host and the MPI 6000 uses
the following UDP/IP fast Ethernet communications data acknowledge message as
shown here:
<len> <msgSeqNum> <cmd> <cmdSeqNum> <resp> <msgSeqNumAck> <checksum>
where
<len> - length, word that specifies the number of bytes in the entire messa
ge.
<msgSeqNum> - message sequence number, byte that specifies the message sequenc
e
number of the message. See the software communication sequence number controls
section for details.
<cmd> - comma
nd, word that specifies
the system command. See the command sec-
tions for details.
<cmdSeqNum> - command sequence number, byte that specifies the command
sequenc
e number of the message. See the software communication sequence number
controls section for details.
<resp> - response, word that specifies the system response. See the response
sections
for details.
<msgSeqNumAck> -
message sequence number acknowledge
, byte that specifies the
message sequence number of the message being acknowledged. See the software
communication sequence number controls section for details.
<checksum> - checksum, byte
that specifies the checksum of the message.
Command Response Message
The MPI 6000 after receiving command request messages from the host sends com-
mand response messages to the host.
The host and the MPI 6000 uses the following UDP/IP fast Ethernet communications
command response message
shown here:
PRELIMINARY