20
CIT 400
pressure and level
7.2 Interface level measurement
given:
tank (max. level 7 m); medium: water, probe 4-20 mA, measurement range 10 m
required: pen recorder on analogue output 4-20 mA, final peak of pen recorder 20 mA at 7 m;
the process transmitter has to indicate the max. filling level of the tank; relay 1 should
have the function of a limit value switch (on = 6 m; off = 5 m)
Please note that the values in "S1on" and "S2on" usually have to be higher than the values
in "S1of" and "S2of". To exchange the switching points, please use the menu contact invert-
ing ("In 1" and "In 2")
switch-on point > switch-off point
switch-on point < switch-off point
Programming
Select the menu "dlS1" in the menu level "dlSP".
Set the following values in the menu level "SinP":
ZPIn
=
0
(starting point of measuring range)
EPIn
=
10
(end point of pressure range)
dP
=
2
(decimal point position)
Select the menu "1" in the menu level "rELn" and set the following values:
HY 1/CP 1 =
HYon (hysteresis mode)
S1on
=
6
(switching point relay 1)
S1of
=
5
(reset point relay 1)
In1
=
St
(Set point inverting relay 1)
Set the following values in the menu level "Aout":
outY
=
4-20
(output signal in mA)
ZPou
=
0
(min. measured value)
EPou
=
7
(max. measured value)
ON
S1on / S2on
OFF
S1of / S2of
OFF
ON
ON
OFF
OFF
S1on / S2on
ON
S1of / S2of
ON
OFF
OFF
ON
