16
MAN-100414
SITRANS TCSC - Operating Instructions
55492-EN-170907
ated when switch-on pulse monitoring is activated. If this does not
correspond to the definition or is completey missing, the SITRANS
TCSC displays a fault. A function test is only triggered by pressing
the test key. This function test is not carried out automatically when
switching on the SITRANS TCSC.
Note:
When connecting sensors without this defined switching sequence,
the switch-on monitoring must be deactivated.
With these switches you can delay the changeover of the relays by
the set time. This can be useful, e.g. with fluctuating product surfaces,
for preventing unwanted switching commands. The switch-on/off
delays can be set independently of each other. If both switches, e.g.
of the switch-on delay, are activated, the times sum up. Delays of 2, 6
or 8 seconds can thus be adjusted.
Information:
Keep in mind that the switching delay of the sensor and signal condi-
tioning instrument accumulate.
The following functionalities can be selected via this switch:
•
Single point control (double channel level detection with one sen-
sor each and the same switch on/switch off point)
•
Two-point control (level detection with two sensors and different
switch on/switch off points)
As opposed to single point control, two-point control allows the
switch-on and switch-off points to be set at different locations (hyster
-
esis). Through the installation or the distance of the two sensors, the
hysteresis can be defined individually. Here, the max. level must be
set to sensor input 1, the min. level to sensor input 2.
The two-point control is used for example when filling and emptying
is carried out via a pump. The filling of a vessel can be for example
switched on at 10 % and switched off again at 90 %. The output of the
second channel behaves identically like the first channel provided the
same mode is set. By changing the mode, the function of the relays
can be inverted.
When level switches SITRANS LVL200 in two-wire version are con-
nected, a function test can be carried out. The test key is recessed
behind the front plate of the signal conditioning instrument. Press the
test key for at least two seconds with a suitable object (screwdriver,
pen, etc.).
By pushing the test key, the circuit to the sensor is interrupted and a
restart of the sensor is initiated. Through this, the conditions fault sig-
nal, empty and full alarm are simulated. The complete test procedure
takes approx. 5 seconds. After correct function, the red failure LED
should not light and depending on the status of the sensor, the relays
are energized or deenergized.
Switch-on/Switch-off
delay
Two-point control
Test key