PDU–4xx–W
©
Dinel, s.r.o.
28
8.4. Control of the relay outputs
The control of the object (measured signal) is realized via relay outputs. Front panel LEDs named
„R” indicates the state of particular relay output.
Optical indication of the exceeding of the main thresholds is independent on the number of relays
installed in the unit.
Modes of the control can be changed depend on the values of parameters
“SEtP”, “SEt2”, “HYSt”,
“modE”, “t on”, “toFF”, “unit”
and
“AL”
. Depend on
“modE”
parameter, relays can be not used
or controlled over one or two thresholds values.
If one threshold is used (Figure 17) the relay can be turned on (
“modE” = ”on”
) or off (
“modE” =
”oFF”
) when the input signal value is contained in zone A.
Fig. 17: One threshold control of the relay/LED outputs
If two thresholds are used (Figure 18) the relay will be turned on when value of input signal is
contained in
zone A
(
“modE” = ”in”
) or
zone B
(
“modE” = ”out”
) and turned off if the signal is
contained in the second one.
Fig. 18: Two threshold control of the relay/LED outputs
One threshold mode
Figure 19 presents the principle of relay outputs operation for one threshold mode, and an example
values of other parameters.
Parameter “SEtP” sets a threshold of the relay, and parameter “HYSt” sets a hysteresis of the relay
(Figure 19 a). The relay can change his state only when input value exceeds (over or under) border
value and tA ,tB ,tC ,tD times (Figure 19) are bigger than the time defined by parameters “t on”,
“toFF” and “unit”. Border values means values equal thhysteresis 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 a C, Fig. 19 a, b, c).
state of
relay / LED
measure
"HYSt" parameter
zone A
zone B
state of
relay / LED
"SEtP" or "SEt2" parameter
measure
"HYSt" parameter
zone B
zone B
zone A
