Rockwell Automation 1775-KA PLC-3 Communication Adapter Module User Manual - Manual (Page 103)

Computer to PC Communiation
Chapter 9
9Ć4
Figure 9.2
The Application, Network and Data Link Layer of RS-232-C Communication (Full or
Half-Duplex)
CMD STS FNC ADDR DATA
DST SRC CMD STS TNS
Data
(From Application Layer)
DLE STX
Data
(From Network Layer)
DLE ETX
BCC
Full Duplex Link Packet and Half–Duplex Slave 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
Half–Duplex Master Message Link Packet
10037–I
Data Link
Layer Packet
Data Link
Layer Packet