Using Native Mode Pad Messages - Allen-Bradley 1779-KFMR User Manual

Using Native Mode PAD
Messages
When you send or receive a PAD command in the Native mode, it
contains all of the fields shown in Figure 11.1. The hexadecimal value of
the SEL field is 06. The STS value is 00. The TNS value distinguishes it
from other PAD commands generated by its message initiator. The LINK,
NODE, and USER values define the destination.
Command Format:
STS TNS LINK
2 Bytes
00
SEL SSQ EXT
06 FF
When a host computer for a 1779-KFM interface receives a PAD
command, it must not send a PAD reply. However, when a host computer
sends a PAD command, the 1779-KFL or 1779-KFM interface at the
destination automatically sends a PAD reply.
Reply Format:
STS TNS LINK
2 Bytes
xx
SEL SSQ EXT
86 FF
When you receive a PAD reply, it does not contain the application-layer
data field of the command. However, the reply contains all of the other
fields in Figure 11.1. The SEL value is 86. The TNS, LINK, NODE, and
USER fields are copied from the command; this helps the command
initiator of your host computer match the command packets with the
Chapter 11
PAD Message Set
DATA (Any Format)
238 Bytes Max.
NODE USER DATA
DATA
NODE USER
DATA
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