Справочник Пользователя для EMSA HS500E
C H A P T E R 5 : E T H E R N E T / I P P R O T O C O L
5 . 5 . 1 E t h e r n e t / I P
H a n d s h a k i n g
To ensure that messages to and from the HS500E are properly delivered and
received, a handshaking mechanism has been implemented that uses a pair of
dedicated words in the exchange. The first two words in each Controller Tag are
dedicated to handshaking.
received, a handshaking mechanism has been implemented that uses a pair of
dedicated words in the exchange. The first two words in each Controller Tag are
dedicated to handshaking.
When new information is generated, the producing device (data producer) increments
a counter, and the consuming device (data consumer) copies that same counter
value to another memory location to signal that the information has been processed.
a counter, and the consuming device (data consumer) copies that same counter
value to another memory location to signal that the information has been processed.
5 . 5 . 2
E t h e r n e t / I P H a n d s h a k i n g E x a m p l e
In the example below, EMS_READ1 is the Read Tag for Node 1 and EMS_WRITE1
is the Write Tag for Node 1.
is the Write Tag for Node 1.
NOTE: [0] indicates the first word, [1] indicates the second word in a Controller Tag.
1 The PLC writes a command to the Output area (of the Read Tag) and then
increments the counter in EMS_READ1 [1].
2 The counter in EMS_READ1 [1] is copied by the HS500E to EMS_WRITE1
[0] which acknowledges that it received the command.
H S 5 0 0 E – O P E R A T O R ’ S M A N U A L
P / N : 1 7 - 1 3 0 5 R E V 0 2 ( 1 2 - 0 5 )
P A G E 4 8 O F 8 2