I use an F411/2 switch to control and to monitor the status of motorized water valves (UP or DOWN), the configuration M=4 keeps the status of the motor, permanently, but after a bus blackout the status of the switch goes back to STOP, which is an unknown state for the motorized valve that has only two states: OPEN or CLOSED.
- QUIZ: How can we recover the status of an F411/2 controlling a motorized valve, or a shutter, after a blackout? HINT: the F425 recovers the status of lights only, after a blackout.
Here is the solution to the quiz.
Because the memory module F425 works only with the light switches (WHO=1) one must use two light switches to control and to recover the status of the motor after a blackout. Therefore, let’s suppose that we use L1 and L2 switches for one motorized valve, or one shutter, and that we use the MH200N with a forced_up and a forced_down scenario:
The L1 and L2 switches have two stable conditions:
Normal DOWN_STATUS: L2=ON and L1=OFF, and
Normal UP_STATUS: L2=OFF and L1=ON
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There are two scenarios in the MH200N:
FORCED_UP SCENARIO: WHEN L1=ON ONLY_IF L2=ON THEN L2=OFF -- GOES INTO AN UP_STATUS, and
FORCED_DOWN SCENARIO: WHEN L1=OFF ONLY_IF L2=OFF THEN L2=ON -- GOES INTO A DOWN_STATUS
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SUMMARY:
L2 L1
0 0 >> 1 0 DOWN_STATUS
0 1 UP_STATUS
1 0 DOWN_STATUS
1 1 >> 0 1 UP_STATUS
The user controls and monitors the motorized valve, or the shutter, using only the L1 switch only, ON is UP (01) and OFF is DOWN (10). The L2 switch is controlled by the MH200N scenarios: The status 0,0 (or STOP) and 1,1 are only momentarily and they do not damage the motorized valve because there is a microswitch and the end positions of the shutter or valves that turns OFF one of the two lines (UP or DOWN) depending on the position of the valve or shutter.
CONCLUSIONS:
The memory module F425 could be used, after a blackout, to recover the status of a shutter (or a motorized valve). This is a good reason to re-install the F425 module.