User manual for meter with U/I input PD72S
6.3.1. One threshold mode
Figure 6.6 presents the principle of relay outputs operation for one threshold mode, and an
example values of other parameters.
Description:
A, B, C, D
- points where measured signal exceeds border values (expected value ± allowed deviation)
B
ON
,
B
OFF
,
D
ON
,
D
OFF
- relays state changes moments: (for
“t on”
> 0,
“toFF”
> 0)
t
A
,
t
B
,
t
C
,
t
D
-
time periods while input signal is in zone A or zone B
Figure 6.6.
Principle of LED/relay output operation for one threshold mode
Parameter
“SEtP”
sets a
threshold
of the relay, and parameter
“HYSt”
sets a
hysteresis
of
the relay (Figure 6.6 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 6.6)
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 6.6 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 6.6 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 6.6 a, d, e).
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