Technical details about detecting the failure of the supply voltage

Power supply units with an integrated rechargeable buffer battery (PSU DC+ ) enable a message to be issued in the event of a supply voltage failure. However, generation of an alarm must be activated via the relevant parameter in the "Basic settings" configuration section (see Basic settings).

As soon as the supply voltage fails and subsequently the output voltage of the power supply unit VPSU OUT (see Block diagram) falls below 9 V , this initiates the malfunction message to be issued, as long as a time delay for issuing the malfunction message has not been entered via the "Delay for power off alarm" parameter in the "Basic settings" configuration section (see Basic settings). The fact that the value has fallen below the threshold is definitely entered in the device log with the "MODULE INFO (403), 1" log entry. If the output voltage of the power supply unit continues to fall, the power supply is switched to the rechargeable buffer battery. This second threshold on the PSU DC+ is dependent on the state of charge of the rechargeable buffer battery (7 V when fully charged, 6 V when practically discharged). If a time delay has been configured, the 4-Channel Data Logger continues to operate normally until the time delay has elapsed. If during the time delay, the output voltage of the power supply unit once again rises above the threshold (6 V to 7 V on the PSU DC+ ) that is dependent on the state of charge of the rechargeable buffer battery, then the rechargeable buffer battery switches back to the supply via the output voltage of the power supply unit. If the output voltage of the power supply unit increases further and also exceeds 9 V , this is entered in the device log with the "MODULE INFO (403), 0" log entry. If the output voltage of the power supply unit is below 9 V when the time delay elapses then issuing of the malfunction message is initiated.

The device establishes a connection to the server to issue a malfunction message. Any outstanding data is also transmitted to the server during this process. The outputs are then deactivated and all operations with the exception of monitoring the output voltage of the power supply unit and the cyclical transmission are shut down. No measurement data is determined in this state.

If it was switched to the rechargeable buffer battery it is only possible to establish a connection with the sever as long as the internal supply voltage Vbatt (see Block diagram) is above 3,4 V . The modem is deactivated from this threshold and the "UV MODEM LOCKOUT" log entry is entered in the device log. This means that the connection is disconnected if the device is in "online" mode or is logged in to the mobile network ("Interval & wakeup" mode). Once this threshold has been reached, a connection establishment cannot be triggered manually via the button (see Solenoid switch) or automatically via the system. If the internal supply voltage falls below 2,9 V , the 4-Channel Data Logger switches to energy saving mode. The "UV LOCKOUT" log entry is also entered in the device log during this process. This state is maintained until the rechargeable buffer battery is fully discharged or the output voltage of the power supply unit rises above 9 V again. The 4-Channel Data Logger resumes normal operation above 9 V . A hardware-based controller in the power supply unit ensures that the rechargeable buffer battery is charged as soon as the supply voltage is available again.

VPSU OUT Output voltage of the power supply unit
Vnotify Threshold at which the malfunction message is issued: 9 V
Vbackup

Threshold for switching to supply via the rechargeable buffer battery:

PSU DC+ : 6 V to 7 V (depending on the state of charge of the rechargeable buffer battery)
tdelay Time delay for issuing the malfunction message – is configured via the "Delay for power off alarm" parameter located in the "Basic settings" configuration section (see Basic settings).
Vbatt Voltage of the rechargeable buffer battery

Supply of the 4-Channel Data Logger

1
  • The "MODULE INFO (403), 1" log entry is created.
2
  • The power supply is switched to the rechargeable buffer battery.
  • The device continues to work normally.
3
  • The time delay for issuing the malfunction message has elapsed.
  • The malfunction message is issued. The outputs are deactivated and all operations with the exception of monitoring the output voltage of the power supply unit and the cyclical transmission are shut down.
4
  • The device switches from the rechargeable buffer battery to the supply via the output voltage of the power supply unit.
5
  • The 4-Channel Data Logger resumes normal operation again.
  • The "MODULE INFO (403), 0" log entry is created.
6
  • The "MODULE INFO (403), 1" log entry is created.
7
  • The power supply is switched to the rechargeable buffer battery.
  • The device continues to work normally.
8
  • The device switches from the rechargeable buffer battery to the supply via the output voltage of the power supply unit.
9
  • The output voltage of the power supply unit once again exceeds the threshold for issuing the malfunction message.
  • The time delay for issuing the malfunction message has not elapsed yet.
  • The "MODULE INFO (403), 0" log entry is created.
  • NO malfunction message is issued.