Allen-Bradley 1779-KFMR User Manual page 99

PAD Message Set
You can send and receive PAD messages between your host device and
the 1779-KFM interface only if you select either the Native or PAD mode.
The message header format depends upon which of these two modes you
select.
PAD messages let devices communicate over the Data Highway II
network in a packet assembler/disassembler message format. With PAD
message format, a device with only enough intelligence to provide the
HDLC link-layer protocol can communicate with other stations in the
Data Highway through the 1779-KFM interface. PAD format is also
useful for devices, such as robots, which have a fixed message format. In
sending a message to a robot, a computer could encode the message data
field with the format that the robot expects. At the receiving node, the
interface disassembles the packet and sends only the data field to the
robot. Since the computer encodes the data field, the robot sees the
format it expects.
PAD messages are described in Chapter 11.
Station Management Message Set
You can send and receive station management messages between your
host device and the 1779-KFM interface only if you select the Native
mode.
Use these commands to configure and alter the network parameters of
station interfaces in the Data Highway II network. For example, you can
set the token-hold time or change the value of a diagnostic timer using
station-management commands.
When you first install your network, you will probably use
station-management commands to set network parameters at each node.
Later, you may use station-management commands to adjust network
parameters. The station management message set is described in
Chapter 12.
Chapter 7
Introduction to Message Sets
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