Fuji Electric ALPHA5 Smart - Page 519

CHAPTER 13 RS-485 COMMUNICATIONS
Modbus RTU Communications 13-31
13
7. Communitacation methods
<Unicast method>
Messages are sent in the following order in this method: (1)  (2)  (3)  (4)  (5)  (6).
<Broadcasting method>
A transmission message is sent to slaves simultaneously in this method. No response message
is sent back.
Host controller
(master)
(1) Transmission message
(2) Response message
(3) Transmission
message
(4) Response
message
(5) Transmission
message
(6) Response message
Host controller
(master)
(1) Transmission message
(1) Transmission
message
(1) Transmission message