i-Catcher Device Control

How we set up remote control

The device control demonstration consists of two lights and a fan that are controlled via the i-Catcher Console in our office. The i-Catcher system has about 20 cameras connected, some of which are analogue cameras and others are IP devices.

For this demonstration we have connected the I/O outputs from an Axis 241Q video server to a Velleman relay board. This board then uses the relays to switch the various devices on and off. The image on the right shows how the equipment is connected together.

Axis Video Server

The Axis 241Q video server has an I/O connector at the rear (the green block in the image to the right) containing four I/O lines, which can be controlled by software to be in one of two states. When set to "Open Circuit" the I/O line is not connected to anything, effectively putting it into the "off" state.

When set to "Grounded" the I/O line is connected to the 0V/GROUND connection. While this does not connect the line to a positive voltage, it can be used to control "active low" equipment such as the Velleman Relay Board.

For those who are familiar with electronics, a 4.7kΩ resistor between the I/O line and +5V converts the "Open Circuit" state to a +5V level, allowing it to be used as a logic level for other equipment.

Each I/O line has an accompanying ground connection. This needs to be connected to the relay board's ground connection, of which the relay board provides one for each input.

Relay Board

The Relay Board is built from a kit of parts, however other relay boards are available ready assembled. The board operates in an "active low" mode. This means that a 0V/Grounded input turns the relay on, and a disconnected or non-0V connection turns the relay off.

The board consists of 8 relays, each with a control input (which we have connected to the Axis Video Server), and two terminals for connecting equipment. When the relay is switched on, the two terminals are connected together. The relay board requires its own separate power supply to operate, independent from any power supply that may be connected through the relay terminals.

Appliances

The appliances themselves are connected simply by wiring their live mains connection via the two relay terminals. Thus, the wiring of the live connection is plug to relay to appliance. The neutral and earth connections are made direct from the plug to the appliance.

The control of the devices can now be achieved from a user at the i-Catcher Console screen, or live from the standard web view. The software was set up by configuring a sensor to use the Axis video server as the device, and specifying the I/O line to control. The Axis 241Q video server allows up to four devices to be controlled independently in this manner. Other Axis devices with I/O lines can be used in the same manner, including many of the Axis cameras.

If you want to create a custom page as we have done, then you can use the information from our i-Catcher API pages to embed the functions into your web page. This allows you to create a custom solution, either for home automation or general device control.

Other controller devices

i-Catcher Console can also read the state of an I/O line configured as an input, and can display its state in a text overlay. The software is also capable of controlling and reading other devices and sensors, including the Watchport sensors from Digi, and the AxxessID Access Control system. This allows i-Catcher Console to integrate into a very flexible security system.