The KTA-225 is a USB or RS485 controlled IO module for interfacing PCs to real world applications, such as controlling lights and sprinkler systems, reading sensors and monitoring switches or analog signals.
The Relays are capable of switching up to 5A at 250VAC, 10A at 120VAC and 10A at 24VDC but the PCB tracks will only handle up to about 5A. A simple ASCII protocol allows control from Windows/Mac/Linux using either USB Virtual COM drivers or RS485. Additionally, multiple devices can be connected to one RS485 bus, allowing control of many devices from one USB port.
The KTA-225 has relays with 12 V DC coils and requires an 9 to 15 VDC supply. The KTB-225 has 24 V relays and requires a 18 to 28 VDC supply but is otherwise identical.
This controller is based on the hardware of the KTA-223 controller, but the number of analog inputs has been increased at the cost of the digital inputs. It can be programmed as a stand-alone controller using the free, open source Arduino environment. Internally, the controller is “shield compatible”, allowing the use of many extension boards designed for the Arduino Deumilanove.
As shipped the controller is loaded with a sketch or program that receives simple commands over the USB or RS485 serial port and switches relays or responds with the status of the analog inputs.
Multiple controllers can be connected to one or more PCs in an RS485 network. Each controller can be assigned an address and will respond to commands addressed to them.
An example program has been written and VB express 2010 to show you how to interface with the KTA-225 using a PC.
New in Version 3:
The newly revised KTx-225 have just arrived! As of mid December, we're shipping out version 3 of the KTx-225. It's fully compatible with the previous versions, but has a range of new features including:
- New relays with higher contact to coil isolation voltage for safer switching of loads
- Power, Tx and Rx Leds Visible from the outside of the box
- Redesigned serial and USB circuitry and layout for higher baudrates, better reliability and better noise immunity
- Changes to the layout inside to match the changes made with the Arduino Uno
Web Interface Sketch:
Using the WebUi sketch and an Ethernet shield allows you to control the Relays and read the Analog Inputs from a web browser
WiFly Interface Sketch:
Check out this item news for a tutorial on using the WiFly shield to control the IO from a web browser