7
Probe error
6*
(assigned)
(“No”) please
check probe: “No”
5*
2 mA
A: no power / state of rest
F: no power / state of rest
Z: assigned without power;
Rest: depending on
assignment / progr.
Probe error
6*
(not assigned)
(“No”) please
check probe: “No”
5*
2 mA
A: activated
F: no power / state of rest
Z: depending on assignment /
programming
1*
Fully lit LED: continuous light / half lit LED: flashing
2*
Description:
“A” Alarm output
“F” Error output
“Z” Assigned output
3*
Example:
12 probes / 4 submerged:
...mA = 9.3 mA (4mA + (16mA / 12) * 4)
16 probes / 7 submerged:
...mA = 11.0 mA (4mA + (16mA /16) *7)
15 probes / 13 submerged:
...mA = 17.9 mA (4mA + (16mA /15) *13)
4*
When using 2 power supply units
5*
Example
6*
See Chap. 7 Special features of system setup
7*
As LLW/HHW-Alarm has priority, this message is shown. However, considering the LED-display (yellow flashes also) the
probefault is recognisable.
Safe operating mode during which the output contacts of the device go into rest position,
corresponds at the same time to the de-energised state of the control unit.
The DU (optional) display unit can be used as a remote indicator. The status LEDs show the same as
the LEDs of the CU. In addition each probe is linked to an LED. Green shows a submerged probe, red a
probe in the steam space and a flashing LED means a probe in an incorrect state. The output current
of the 4 mA .. 20 mA output of the DU is calculated like that of the CU.
4.3 Setup
For ensuring high availability IGEMA recommends the use of 2 power supply units (redundancy). In
terms of hardware the CU is designed for operation with 2 power supply units.
Both the measuring unit (MU) and the control unit (CU) have 2 independent electronic circuits with
their own processors. All processors carry out regular self-tests for internal faults in the electronic
circuit. This provides self-monitoring of the device and thus a higher safety standard.
Measuring unit:
Both electronic circuits record the state of the probes and send it to the control unit.
Control unit:
Both electronic circuits evaluate the status messages of both electronic circuits of the measuring
unit. If both status messages are identical the required reaction (Chap. 4.2) is carried out.
A plausibility check takes place.
