Siemens 353 - RLM - Rate Limiter

UM353-1B Function Blocks
April 2012
3-81
3.2.74 RLM_ - Rate Limiter
RLM_ function blocks limit the rate of change of analog
input A. Separate up and down rates are entered in
configuration, in engineering units per minute. Output RL
will be high (1) if the block is limiting a rising input signal
and output FL will be high when the block is limiting a
falling input signal.
The Adaptive Rate inputs will vary the configured adaptive
rate between 0 – 100% as the input varies from 0 to 100%.
When the input is not configured the adaptive rate will not
apply.
Input E asserted high (1) will enable the limit action of the
block. When input E is low (0), the output will track the
analog input. If input E is not configured, the limit action of
the block will be enabled
BLOCK DIAGRAM
A
O1
E
E
nable
UPRATE
DOWNRATE
A
nalog Input
O
utput
1
RL
FL
R
ising
L
imit
F
alling
L
imit
.
.
Switch shown in the enabled position with Input E not connected
AU
AD
A
daptive Rate
U
p
A
daptive Rate
D
own
Rev. 2
A
nalog Input
RATE LIMITER
ER
D
IN U A
UP RATE
(units/minute)
(S)
....... Real (100.0)
INPUT A
(H)
..... loop tag.block tag.output (null)
O1
O
utput
1
RATE LIMITER
RLM_
ESN =
000
ATP
TP
A
ESN
E
xec.
S
eq.
N
o.
(H) ............ 001 to 250
E
nable
E
FL
F
alling
L
imit
U
OW R EAN
IN U ETP
INPUT E
(H)
.....
loop tag.block tag.output (null)
T
DOWN RATE
(units/minute)
(S) . Real (100.0)
RL
R
ising Limit
IN UTP
IN UTP
A
A
U
D
INPUT AU
(H)
..
loop tag.block tag.output (null)
INPUT AD
(H)
..
loop tag.block tag.output (null)
A
daptive
U
p
AU
A
daptive
D
n
AD