User manual - METER SRT-457
Parameter
SEtP
sets a
threshold
of the relay, and parameter
HYSt
sets a
hysteresis
of the relay (Figure 6.4 a). The relay can change his state
only
when input value
exceeds (over or under)
border value
and
t
A
,t
B
,t
C
,t
D
times
(
Figure 6.4
) are bigger than the
time defined by parameters
t on
,
toFF
and
unit
.
Border values
means values equal
threshold
+
hysteresis
and
threshold
-
hysteresis
respectively.
If
t on
and
toFF
parameters
are set to 0 , then the relay state will be changed
as soon
as input value exceeds any of the
border values
(see points A and C, Figure 6.4 a,
b, c).
If values of
t on
or/and
toFF
are positive, then relay state will be turned on if the
input value exceeds the
border values
and stay bigger (or lower) during at least
t on
(see points B
ON
, D
ON
, Figure 6.4 a, d, e). Similarly, the relay will be turned off if time
toFF
elapse since the input signal value exceeds any of the
border values
(see points
B
OFF
, D
OFF
, Figure 6.4 a, d, e).
If t
A
,t
B
,t
C
or t
D
(when input signal stay in
zone A
or
zone B
) are lower than parameters
t on
or
toFF
, the relay will not change his state (see points A and C, Figure 6.4 a, d, e).
The state of relay output while the input value exceeds the
border values
(points A, B, C,
D) is described by parameter
modE .
The relay can be turned on (
modE
=
on
), or
turned off (
modE
=
oFF
) when input signal value is contained in
zone A
(Figure 6.4 a).
The parameter
AL
allow user to set the relay output behaviour in critical situations (e.
g. Input values exceeds
permissible measurement range
)
.
User can select that the relays
will be turned on, turned off,or not changed in critical situations.
All parameters connected with relay outputs are described in paragraph
rEL1 menu
.
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