Rockwell Automation 1775-KA PLC-3 Communication Adapter Module User Manual - Manual (Page 132)

Half-Duplex Protocol
Chapter 11
11Ć5
Figure 11.1
Formats for Half-Duplex Protocol
DLE ENQ STN BCC
a) Polling Packet
CMD STS FNC ADDR DATA
DST SRC CMD STS TNS
Data
(From Application Layer)
DLE STX
Data
(From Network Layer)
DLE ETX BCC
b) Slave Message Link Packet
From
Application
Layer
From
Network
Layer
From
Application
Layer
From
Network
Layer
CMD STS FNC ADDR DATA
DST SRC CMD STS TNS
Data
(From Application Layer)
DLE SOH STN DLE STX
Data
(From Network Layer) DLE ETX
BCC
c) Master Message Link Packet
10051–I