7
Description
Input terminals
1(+) signal loop (4…20mA)
2(-) signal loop
3Not used, can be used as a spare terminal
Voltagedropin4..20mAinputloopismax4.8V.This
corresponds 240ohmloopresistance.Whenalarms
are used (optional) voltage drop is max 7,3 V. Input
is secured for reversed polarity and over current
tolerance is 100 mA.
Alarm connections, only models 302 and 306
6,7Lowlevelalarm,displayislowerthanalarmlevel
4,5Highlevelalarm,displayishigherthanalarmlevel
Solid state relays,SSR: max. 250 V ±DC/AC,
150 mA, 12 ohm. Isolation between input loop 4 kV.
Alarms can be taken into use by removing jumper
inside the case. Voltage drop will increase to 7,3 V.
Measuring mode
Thisis normaloperating mode.Scaled inputsignal is
in display. LED indicator functions are:
A1 = Low level alarm
A2 = High level alarm
Conf = Unit in configuration or calibration mode
Measuring mode can be changed to Configuration
modebypressingsimutaneously▲★-keys.Ifaccess
code is used it must be entered when display shows
Code.
Configuration mode
Undo,Save➤➤
➤➤
➤
Exit from configuration mode. SAVE saves new
configuration and Undo exits without saving.
AL L, AL H ➤➤
➤➤
➤
Alarmlevels(L=low,H=high).Bothalarmscannotbe
energized at the same time. Therefore low level
cannot have higher value than high alarm and vice
versa.
If input signal is under 3 mA relays will be de-
energized. (Normal open 'NO' relays need energy to
be closed).
ALHy➤➤
➤➤
➤
Alarm hysteresis is number of digits below or above
selected alarm level (both sides have same value).
Normally alarm relays are enegized when display
value goes to alarm level and de-energized when it
goesoverhysteresisvalue.
Alarms can also have manual reset when hysteresis
value is set larger than measuring range (full span).
Manual reset is done with ▼-key from front panel.
An example of Manual reset / hold function:
High level alarm is 100 °C and low level -5 °C. When
inputisover100°C,LEDA2 lits(relayA2energized)
anditdon'tgooffeveniftheinputgoesbelow100°C.
It must be resetted manually with front panel key ▼.
Alarmwillberesettedalsoifinputgoesbelowselected
low level (-5°C). That is because both relays cannot
be energized at the same time. If You do not want to
usethispossibilitygivenbytheotheralarm,selectit's
value outside that the scaled range (not in use).
Alarms off
Negative hysteresis value disables alarm function.
Dec➤➤
➤➤
➤
Decimal selection 0..3, i.e. 0.9, 0.99 or 0.999
Lo, Hi ➤➤
➤➤
➤
Lo andHi scalesdisplay toinputsignal4..20 mA.Lo
value is selected for input 4 mA and correspondingly
Hi value is for 20 mA input.
e.g. 4..20 mA = display Lo -100.. Hi +200
Filt➤➤
➤➤
➤
Display Filter. This fucntion stabilizes display value
when wide measuring range is used.
Filtervaluecanbesetbetween1(min)..0.010(max).
1.000 = no filter
0.200 = normal filter
e.g. 0.2 =(1/5) one new measurement and 4 old
values or
0.1 = (1/10) one new + 9 old values (slower)
Alarms are controlled with the filtered value (filter
affects to alarms reaction time).
Inte➤➤
➤➤
➤
Display intesity (brightness). You can change the
intensity with ▲▼-buttons. Hold ▼-key to decrease
intensity and vice versa.
Inmeasuringmodeintensitydecreasesautomatically
when input is under 6 mA.
TrF➤➤
➤➤
➤
Transfer function selection.
Lin = normal fnction
Sqrt = square root function
CFCo➤➤
➤➤
➤
Access code for configuration mode. Access code is
formed with ▲▼★➤-keys. Code is formed with six
pushes of front panel buttons. Not in use when code
issetto(★★★★★★)(factorydefault).
If configuration access code is forgotten, all the
settings can be returned to factory defaults (not
calibration) by holding down buttons ★and ➤while
connecting input signal 4..20 mA.
