Manual MC3-TM Temperature Monitor
Documentnr.: 131083 version 2.1
Page 13 of 16
7.
Alarms
In case a measured temperature value reach one of the alarm temperatures the alarm output is
triggered. It lowers or raises the output voltage according to the configured value (see 6.1 Temperature
Monitor config).
A single alarm output is used for any combination of errors.
The alarm value can be read by reading Modbus register 100. Each bit represents a different alarm.
The possible errors are:
Bitnr Description
Cause
Solution
0
Cold water temperature
sensor defect
The measured cold water
temperature is outside the
controller temperature range (-50.0
°C - +50.0 °C). Either the sensor is
defect, not correctly connected or a
wrong sensor type is connected.
Check the sensor connection
or replace the sensor.
1
Hot water temperature
sensor defect
The measured hot water
temperature is outside the
controller temperature range (-50.0
°C - +50.0 °C). Either the sensor is
defect, not correctly connected or a
wrong sensor type is connected.
Check the sensor connection
or replace the sensor.
2
Minimum alarm cold
water
The measured cold water
temperature is below the configured
minimum alarm value.
Raise the temperature of the
cold water or lower the
minimum alarm temperature
value (Reg 10).
3
Maximum alarm cold
water
The measured cold water
temperature is above the configured
maximum alarm value.
Lower the temperature of the
cold water or raise the
minimum alarm temperature
value (Reg 11).
4
Minimum alarm hot
water
The measured hot water
temperature is below the configured
minimum alarm value.
Raise the temperature of the
hot water or lower the
minimum alarm temperature
value (Reg 12).
5
Maximum alarm hot
water
The measured hot water
temperature is above the configured
maximum alarm value.
Lower the temperature of the
hot water or raise the
minimum alarm temperature
value (Reg 13).
6
Communication error 1 An internal communication error
occurred.
Reset the error and if it
persists, contact VDH
Products.
7
Communication error 2 An internal communication error
occurred.
Reset the error and if it
persists, contact VDH
Products.
8
Communication error 3 An internal communication error
occurred.
Reset the error and if it
persists, contact VDH
Products.
When an alarm occurs, it can be acknowledged by writing the value 0 (zero) to the Modbus register 100.
The alarm output value will return to normal directly, while the value in the Modbus alarm register will stay
the same until the alarm situation has been solved.
