Allen-Bradley GuardPLC 1753, Справочник по безопасности

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104 Publication 1753-RM002C-EN-P - September 2008
Chapter 9 Configuring Communication
t
E
= 24 ms fault, 12 ms normal
t
F
= 6.2 ms + relay response time
t
F
= 6.2 ms + 0
t
F
= 6.2 ms
Worst Case Reaction Times
System Reaction Time with no faults:
T
R
= 16.2 + 12 + 100 + 8 + 12 + 6.2
T
R
= 154.4 ms
System Reaction Time with a single fault:
T
R
= 16.2 + 24 + 100 + 8 + 12 + 6.2
T
R
= 166.4 ms
System Reaction Time with all faults:
T
R
= 16.2 + 24 + 100 + 8 + 24 + 6.2
T
R
= 178.4 ms
The basic equation is:
A + B + C + D + E + F = System Reaction Time (T
R)
The 2 x WDT term is valid as long as the scanner’s Scanner Receive
Timeout is set to the same value as the controller’s Watchdog Timeout.
System Reaction Time with No Faults
Input + 2 x Expected Packet In 2 x Watchdog T Max
Scanner Reaction Time + 2 x Expected Packet In Output
1791DS-
(input)
1753-DNSI GuardPLC 1753-DNSI
1791DS-
(output)
16
.2
+
fil
ter
(n
or
m
al
an
d f
aul
t)
2 *
EP
I (
n
or
m
al
)
CR
T
L (
fau
lt)
2 *
W
D
T
(n
or
m
al
an
d f
aul
t)
M
ax
S
can
ne
r
R
e
spo
n
se
Ti
m
e
(n
or
m
al
an
d f
aul
t)
2 *
EP
I (
n
or
m
al
)
CR
T
L (
fau
lt)
6.
2 C
o
mb
o
o
2
6
.2
R
e
la
y
(n
or
m
al
an
d f
aul
t)
A B C D E F
RSNetWorx RSNetWorx
RSLogix Guard
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