Taking flooding pictures when it matters

taking flooding pictures with a remote data logger

Besides level measurements, taking flooding pictures having visuals of the situation is very useful when assessing risk and impact.

To effectively monitor the situation and make timely decisions, a waterboard responsible for a river with flooding risk can implement a camera system that captures images at specific water levels.

Assume a waterboard wants a camera to take one picture when a warning level of 6 meters has been reached and repetitive pictures every 30 minutes when the critical level of 7.5 meters is exceeded.

How can these two functions be programmed in the YDOC Data Logger to trigger the camera?

An YDOC data logger is not designed as a camera control system, but  with a little bit of creativity the data logger can do both at the same time: Continuous monitoring water levels and taking flooding pictures when it matters.

The ydoc ML-OO-SW option board (V1.06 with the timer functions), can help to achieve the above mentioned functionality.


  • YDOC Data Logger, Camera and ML-OO-SW (V1.06) option board.
  • Water level sensor connected to input port
  • Configured Warning and Alarm levels with hysteresis
  • Configured Calculation channels to trigger the Output Board on warning and alarm levels
  • Digital input port in trigger mode to activate the camera
  • Programmed ML-OO-SW ports to generate one-shot and pulse-train output
  • Wiring diagram to connect the Option Board Output ports and Data Logger  digital input port

How to build this example

In five steps, this example can be build:

(1) Analog input port (water level). In this example, an “pot-meter” type water level sensor (LEV) is used.

(2) Programming the Data Logger to activate a option board output switch, on Warning and Alarm levels.

(3) Set up the ML-OO-SW ports characteristics to deliver a one time pulse and pulse interval for camera triggering.

(4) Coupling the digital input port to the camera.

(5) Wiring the ML-OO-SW output port and Data Logger digital input port connectors.

These five steps are showed in detail, to complete the set up for this camera example.

(1) Set up the sensor.

In this example, desired levels are 6,0 m for the one-shot and 7,5 m for the half-an-our shots. Hysteresis (0,5 m) is involved to prevent unwanted camera shots on minor  water level changes. (Like waves or small level differences around the chosen alarm levels). Water level parameter name will be “LEV”. Also, choose appropriate values for data log and send intervals, in the General Settings.

Setting flooding alarm levels

(2) Warning and alarm level programming.

The sensor will generate a level value, stored in LEV. Define alarm (ALR) levels “high” and “high-high”. Use calculation channels to trigger the switches on the Output Board.

With an AND function, the ALR state of LEV can be determined:

Available ALR value:                         Alarm level selected:

and(:LEV.ALR;1)                                  low-low

and(:LEV.ALR;2)                                  low

and(:LEV.ALR;4)                                  high

and(:LEV.ALR;8)                                  high-high

For the “Warning Picture”, the “high” alarm is needed, use value 4.

Warning trigger

For “Alarm Pictures”, the “high-high” alarm is needed, use value 8.

Alarm trigger

Each output will activate a switch on the ML-OO-SW board.

The “Warning Picture” calculation is connected to the first OB  port:

The “Alarm Pictures” calculation is connected to the second OB port.

(3) Set up ML-OO-SW activation characteristics.

The output characteristics of OB /SW1 is modified to “Once” and OB /SW2 to “Pulse Interval”.

Go to “Option Boards” and choose “Auxiliary output” the ML-OO-SW board. (Galvanic Isolated Switches).

Use the [X] “Auxiliary terminal” to connect to the ML-OO-SW.

Setup “Switch 1” to generate one-shot pulse. (2 seconds).

Setup “Switch 2” to generate a 2 second pulse, every half an hour.

Exit from the terminal using <Cntrl> Z.

(4) Digital input port.

Configure the camera to take a shot on digital input D1 activation. The camera has a warm-up time of 7 seconds.

Goto “Digital Inputs” menu.

Configure D1 to act as a “Digital trigger input”.

Camera setup.

Choose the appropriate picture size. TCP is used to send the pictures, use “Delete after send” and 7 – 10 seconds camera warm up time. Test the camera.

Taking flooding pictures on digital trigger

The modem has to wait for the camera, to complete the picture storage on de SD card. A send delay of 45 seconds is added.

(5) Wiring.

Option Board Switches are “Open Collector” type. That is why the switches can be wired in parallel. In this way, both outputs are combined to one signal and that is wired to the digital input port. With the wires connected, the ML-OO-SW timer functions are regulating the camera activation for taking flooding pictures.

Option Board connector

Main Board Connectors


Option Board SW1 a/b SW2 a/b are wired in parallel and connected to the Data Logger Main Board X3 (8) digital input, D1 and Gnd. The camera is connected to X5 (5).