Rockwell Automation 1770, D17706.5.16 Ref Mnl DF1 Protocol Command - Manual (Page 55)

Chapter
4
Publication 1770Ć6.5.16 - October 1996
Using FullĆduplex Protocol to
Send and Receive Messages
In full-duplex protocol, devices share the same data circuits, and
both devices can “talk” at the same time. Full-duplex protocol can
be likened to a two-lane bridge: traffic can travel in both directions
at one time. (To compare full-duplex to half-duplex protocol, refer
to Chapter 3, “Using Half-duplex Protocols to Send and Receive
Messages.”)
Read this chapter to help learn how to use full-duplex protocol to
send and receive messages. It contains these sections:
Section Page
FullĆduplex Protocol Message Transmission 4-2
FullĆduplex Protocol Environment 4-3
Message Characteristics 4-4
Transmitter and Receiver Message Transfer 4-4
FullĆduplex Protocol Diagrams 4-10
Link arbitration
You can use these Allen-Bradley interface modules to automatically
handle the link arbitration:
• 1747ĆKE • 1771ĆKE • 1775ĆKA (via modem port)
• 1770ĆKF2 • 1771ĆKF • 1785ĆKE
• 1770ĆKF3 • 1771ĆKG • 5130ĆRM1 (channel one)
• 1770ĆKFC • 5130ĆKA • 5130ĆRM2
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