Device to IP Control Anything - uSwitch RelayBy Brian Rhodes, Published on Jan 13, 2014
A common challenge integrators face is controlling non-networked equipment. Once systems 'go IP', there is typically a desire to stick everything on the network too. Unfortunately, even turning equipment on or off can be a chore requiring manual operation or clunky expensive machine controllers. The uSwitch Relay aims to change all that for less than $150. In this note, we look at the relay, potential security applications, and explore the limits of its usefulness.
The value of uSwitch is defined by the systems it is connected to. The device's greatest utility comes in two primary uses:
LAN Control: When it comes to controlling unnetworked systems or machinery, the uSwitch can be connected to the power contactor or operator to allow internet accessible control. From example, take a security gate operator. The relay can be installed to trip the operator either open or closed no matter if the controller was previously remotely networked or not.
In the same way, high voltage security light circuits, or even machinery like gasoline pumps can be turned on remotely as needed. Video surveillance or access control systems can be used to verify identities, and operators can then use web access to activate the attached systems from a great distance.
Remote Rebooting: Another use of the relay comes from power cycling attached equipment. If a recorder, switch or camera becomes unresponsive the uSwitch permits the basic troubleshooting step (power cycling the equipment) from the internet.
With core platforms like surveillance and access control increasingly being installed as 'pure IP' systems, system designers and endusers alike often find themselves with hands in both networked and non-networked systems. Videogenix's uSwitch in an IP accessible relay that gives a simple network control interface to non-networked devices.
The ~8" X 4" X 1.5" device looks is fully enclosed and essentially contains two relays with contact rated up to 220VAC/15A:
Other details include:
- Flimsy Browser Interface: While the device includes a webserver accessible by all major browsers, the interface is spartan, consisting only of a handful of buttons and dropboxes. None of the buttons or labels can be customized nor able to be repositioned. Controls are simple to learn, but fixed. A screenshot is shown in the image below:
- Internal Timer: Even without manually button actions, the uSwitch has two internal timers (hours/minutes/seconds) that cause the contactor state to automatically change when the setpoint is reached.
- Password Protected: The relay control interface screen is protected by username and password.
- 12/24 VDC External Power: A major limitation is that PoE is not an option. An external inline power supply of either 12 or 24 VDC must be used via connector terminal block
- Inexpensive: The uSwitch has street pricing of less than ~$130. This is a strong advantage compared to PLC based programmable relays that run ~$300, that likely require multiple devices and special software to program.
Similar products to uSwitch are available:
Axis P8221 [link no longer available]: Despite being commonly overlooked as an 'Audio Interface Module', the P8221 contains eight input/output contacts useful in a similar fashion to uSwitch's relays. The Axis module also has the marked advantage of being compatible with many VMSes, so interface buttons can be directly imbedded into screens where uSwitch cannot. However, the P8221's contacts are only rated to 40VDC (not high-voltage AC) and has a moderately higher street cost of ~$330.
Programmable Relays: As noted in our Relays Solve Complex Applications note, many other types of IP addressed relays are common in the machine/systems design world. However, those platforms are generally more complex to program and might even require special training before purchase. In generally, these types of relays offer a higher degree of customized control and software integration, but they are also more expensive costing between $200 - $500 each.
Drawbacks & Weaknesses
While uSwitch can provide great value in avoiding service calls or travel to remote locations, it does not come without drawbacks, namely:
- Raw Interface Only: The relay's webserver is basic and is not integrated into VMS platforms. This means that controlling any system it is connected to takes place in a standalone webpage, requiring separate credentials and may have unclear operating directions.
- Local: The relay is ethernet connected, but is accessible from the LAN only unless additional configuration of switches, routers, or port forwarding is done.
- Dangerous Install: Most security hardware installers are not licensed, trained, nor equipped to modify non low-voltage electrical systems. Using the uSwitch could mean subcontracting an Electrician or Electrical Engineer for safe, proper application.
- On/Off Only: Relay control is simple, typically applying power or taking it away. This means that uSwitch is useful only for basic control of systems, and is not a comparable replacement for controls integration or more complex PLC based modification.