201/232
Building Technologies
Boiler sequence controller RMK770
CE1P3132en
HVAC Products
13 Function block “Faults“
23.04.2009
The fault with the highest priority is sent via KNX bus. If more than 1 fault input with
priority “Urgent“ want to signal a fault, message ”>1 fault input faulty“ is delivered with
the highest priority. Without this fault status message, the message from only 1 fault
input would appear.
The digital status inputs cannot be monitored. We recommend to use wiring ensuring
that the signal drops out when a fault is pending.
13.8.2 Analog fault input with limit value supervision
An analog input can be monitored for limit value crossings.
An input that is already configured can also be monitored. For example, the main flow
temperature sensor can be monitored to ensure that the maximum flow temperature will
not be exceeded.
Main menu > Commissioning > Settings > …
or
Main menu > Settings > Faults > Fault input …
Operating line
Range
Factory setting
Limit value fault on
0 / 1*
1
Limit value fault off
0 / 1*
0
* Depending on the input identifier (the example here applies to a digital input)
If “Limit value fault on“ is greater than “Limit value fault off”, the input is monitored for
overshoot.
Limit value fault on:
80 °C
Limit value fault off:
75 °C
If the temperature exceeds 80 °C, a fault is identified; if it drops again to a level below
75 °C, the fault is considered removed.
ERROR
ON
OFF
313
2D
12
If “Limit value fault off“ is greater than “Limit value fault on”, the input is monitored for
undershoot.
Limit value fault on:
10 °C
Limit value fault off:
12 °C
If the temperature falls below 10 °C, a fault is identified; if it returns to a level above
12 °C, the fault is considered removed.
ERROR
ON
OFF
313
2D
13
>1 fault input fault
Fault handling
Example
Example