FlexiDim™ 8 Channel Optically Isolated Input Module

This Module, which appears like an 8 Button switch to the FlexiDim™ system, is used to connect PIR detectors or push button switches.

The Module is fitted to a double-width blanking plate and should be installed in a wall box (surface mounted or flush as preferred). Typically it will be installed in the same location as the Switch Controller.

A single Cat 5 cable (+12V, 0V, Data A & B) connects to the Switch Controller in exactly the same way as a normal FlexiDim™ switch plate. Up to eight “push to make” or “push to break” (N/O or N/C) contacts can be connected to signal to the FlexiDim™ system.

Connecting switches

A +12V block and 0V are provided on the module. There are 8 inputs, each with a “+” and “– “connection. The switch contact should be connected so that, when closed, a circuit is made from +12V to the “+” input terminal and from the “-“ input terminal to 0V. This is shown below.


If a PIR is used, the +12V and 0V terminals may be used to power the PIR.

A DC voltage may also be used to signal to FlexiDim™. The inputs of the module will accept voltages between 6 and 24V, As the inputs are completely isolated, this does not need to be referenced to the FlexiDim™ 0V line.


Setting Up Normally Closed or Normally Open Operation

When the module is first powered up, the LED will blink red and green for 30 seconds. This allows PIR detectors to initialise and provide a stable output. No data is sent to FlexiDim™ during this time.

Depending on the type of device connected to the inputs, it is necessary to program the module to detect either contact opening or contact closure. This is referred to as ‘normally closed’ or ‘normally open’ operation.

To program the module, hold the button on the module for 10 seconds. The LED will turn on red for 2 seconds and then turn off. The state of each input when the led turns on is considered the normal or quiescent state. Therefore ensure that no buttons are pressed and any PIRs are not detecting movement at this instant.

Auto-repeat operation

With a manual switch, a single message for each press is all that is normally desired. However, with a PIR it is often necessary to inform FlexiDim™ that there is still activity in the area. Unless the PIR stops detecting movement, it will keep it’s output in the active state continually. Therefore, it is necessary to program the Opto module to repeat the message every 10 seconds for as long as that channel is in the active state.

To program an input for auto-repeat operation, trigger that input by pressing the button or by walking in front of the PIR so it detects movement while in programming mode.

When all channels that are to have auto-repeat operation have been triggered, press the button on the module to save the settings and return to normal operation.

Whenever a contact is detected in the active state, a message is sent to FlexiDim™. This appears to the system like a button press, the channels on the opto module corresponding to buttons 1 through 8 on a switch.