Simex SRT-457, User Manual

Page: 17 / 36

User manual - METER SRT-457
6.3.2. Two thresholds mode
Obja nienie:
A, B, C, D, E - points where measured signal exceeds border values (expected value ± allowed deviation)
B
ON
, B
OFF
, C
ON
, C
OFF
, E
ON
, E
OFF
- relays state changes moments: (for t on > 0, toFF > 0)
t
A
, t
B
, t
C
, t
D
, t
E
- time periods while input signal is in zone A or zone B
Figure 6.5. Principle of LED/relay output operation for two thresholds mode
Figure 6.5 presents the principle of relay outputs operation for two thresholds mode, and an
example values of other parameters. In this mode parameter
SEt2
is accessible in common
with
SEtP
, this parameter describes a second threshold of the relay output. The parameters
HYSt , modE , t on , toFF , unit and AL are connected with both SEtP and
SEt2 thresholds. While the controlling process, the relay output changes his state depends
of both SEtP and SEt2 thresholds in similar way as it was described in one threshold
mode.
If two threshold mode is used,
modE
parameter defines state of the relay output when
the input value occurs in a particular zone defined by
border values
of both
thresholds
. The
relay can be turned on if the input value is contained in
zone A
(
modE
=
in
) or
zone B
( modE = out ) and turned off if it is contained in the second one (Figure 6.5).
17
E
OFF
SEtP or SEt2
parameter
HYSt parameter
measure
d signal
displayed value
time
time
time
A
B
C
D
relay state
( modE = in
t on = 0
toFF = 0)
relay state
( modE = in
t on > 0
toFF > 0)
t
A
t
C
t
D
B
ON
relay state
( modE = out
t on = 0
toFF = 0)
relay state
( modE = out
t on > 0
toFF > 0)
toFF parameter
t on parameter
B
OFF
E
ON
time
time
closed
open
a)
b)
c)
d)
e)
open
closed
open
open
closed
closed
t on parameter
toFF parameter
zone A
zone B
HYSt parameter
zone B
C
OFF
C
ON
E
t on parameter
toFF parameter
t
B
t
E