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Self-supervision
output
The annunciator unit is provided with extensive
self-supervision functionality which, in case of
an internal fault or if an internal malfunction is
detected, causes an operation of the self-super-
vision auxiliary output relay. The self-supervi-
sion system monitors continuously the internal
voltages, the program execution and microproc-
essor logic. An internal malfunction of the unit
produces an automatic restart attempt and if the
reason for the malfunction has disappeared, the
normal operation of the annunciator unit con-
tinues.
If the fault on the program, the microprocessor
or the supply voltages is of a permanent nature,
the LED indicator marked FAULT is switched
on and the self-supervision auxiliary output
24 v undervoltage
5 V over- and undervoltage
48 V undervoltage
Hardware and software
watchdog
Fig. 13. Principle diagram for the self-supervision system.
The following fault messages can be shown in
the display:
- - -1 = parameter memory circuit not available
- - -2 = faulty parameter memory (checksum
error)
- - -3 = event register blocked due to field con-
tact "pumping" (se below)
- - -4 = undervoltage in field contact circuit
supply
The serial communication is also supervised.
The decimal point in the corner to the right in
the display starts blinking if there hasn't been
any serial communication within the last thirty
seconds. The blinking decimal point indicates a
fault on the communication bus or in the higher
level system.
If no serial bus is connected to the annunciator,
the bus supervision can be taken out of use. This
is done by giving the parameter V201, "setting
of data transmission rate", the value 1(synch
out), se the section "Selection for the serial
communication port", page 34.
relay drops off (normally energized). At the
same time all the other auxiliary outputs are
locked including the serial communication port.
If the voltage of the logic circuits totally disap-
pears, the LED indicators marked ON and
FAULT are turned off, but in other respects the
functions are as described above.
If a fault occurs in the 48 V DC field contact
voltage, generated by the annunciator unit, the
FAULT LED is switched on and the self-super-
vision auxiliary output relay drops off (normally
energized). The fault information can be sent
over the serial communication. If the control
voltage of the auxiliary output relays disappears,
the self-supervision auxiliary output relay drops
off.
Fault
Internal self-
supervision
To prevent a "pumping" field contact from
blocking the communication to a higher level
system, the unit is provided with a setting to
indicate how many incoming alarms are allowed
from one channel within one minute. In case the
setting limit is exceeded the channel is blocked
until the alarms per minute again goes below the
set value. A channel with a "pumping" field
contact is indicated as follows:
Channel number
"Pumping"
The indication is reset with the RESET push-
button.
The "pumping" supervision is programmed by
parameter S11 (channel related settings):
00 = "Pumping" supervision not in use
01...99 = Maximum alarms per minute
Self-supervision
output relay
1
Reflash and communication
interlocking
15
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