Burkert 8400 Manuel D'utilisation page 23

Adjustment and functionalities
9. ADJUSTMENT AND
FUNCTIONALITIES
9.1. Safety instructions
DANGER
Risk of injury due to electrical voltage
▶ Observe all applicable accident protection and safety guide-
lines for electrical equipment.
WARNING
Risk of injury due to nonconforming adjustment.
Nonconforming adjustment could lead to injuries and damage
the device and its surroundings.
▶ The operators in charge of adjustment must have read and
understood the contents of this manual.
▶ In particular, observe the safety recommendations and
intended use.
▶ The device/installation must only be adjusted by suitably
trained staff.
9.2. General recommendations
All settings may influence the correct running of the process.
→ Note the values of the parameters set in the table in
chapter 9.7.3.
Type 8400
9.3. Functions of the expansion board
in transmitters
8400 transmitters are fitted with a 4...20 mA input and a
4...20 mA output via an expansion board.
9.3.1. 4...20 mA output
The 4...20 mA output provides an electrical current, the value of
which reflects the temperature measured by the device.
9.3.2. 4...20 mA input
The 4...20 mA input is used to modify the commutation
thresholds of the device's relay via the 4...20 mA output on a
controller.
The relay's low (OLO) and high (OHI) commutation thresholds
are determined by a mid-point transmitted by the controller, from
which the device subtracts for OLO or adds for OHI the difference
DELT defined by the user. DELT is a temperature value (expressed
in °C or °F depending on the unit selected), see Fig. 18.
The OLO and OHI thresholds move within a commutation range,
depending on the current value transmitted by the controller, see
Fig. 18.
The lower limit of the commutation range is equal to the temper-
ature corresponding to the 4 mA current minus DELT, see Fig. 18.
The upper limit of the commutation range is equal to the temper-
ature corresponding to the 20 mA current plus DELT, see Fig. 18.
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