Level Pro ITC 450, Руководство пользователя

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Figure 6.7 presents the principle of relay outputs operation for one threshold mode, and an example values of
other parameters.
6.3.1. One Threshold Mode
Parameter
“SEt P”
sets a threshold of the relay, and parameter
“HYSt”
sets a
hysteresis
of the relay (Figure
6.7 a). The relay can change its state only when input value exceeds (over or under) border value and tA,tB
,tC ,tD times (Figure 6.7).) are bigger than the time defined by parameters “t on” , “t oFF” and “unit” . Border
values means values equal thhysteresis and threshold-hysteresis respectively.
If “ t on ” and “ t oFF ” 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 6.7 a, b, c).
If values of “t on” or/and “t oFF” 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 6.7 a, d, e).
Similarly, the relay will be turned off if time “t oFF” elapse since the input signal value exceeds any of the
border values (see points BOFF, DOFF, Figure 6.7 a, d, e).
“SEt P” parameter
(expected signal value)
“HYSt” parameter
(allowed signal
deviation)
A J
C
A B
C
J
ON
OFF
“t oFF”
“t on”
J
OFF
ON
“t on” “t oFF”
relay state
( modE = on
t on = 0
t oFF = 0)
relay state
( modE = on
t on = 0
t oFF = 0)
relay state
( modE = oFF
t on = 0
t oFF = 0)
relay state
( modE = oFF
t on = 0
t oFF = 0)
Figure 6.7. Principle of LED/relay output operation for one threshold mode
Description:
A, B, C, D
B
ON
,B
OFF
,D
ON
,D
OFF
t
A
, t
B
, t
C
, t
D
- points where measured signal exceeds border values (expected value ± allowed deviation)
- relays state changes moments: (for “t on” > 0, “t oFF” > 0)
- time periods while input signal is in zone A or zone B
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