Modbus I/O Module 4DI + 8DO + 3AI (8-28VDC)
PC or PLC based 6.5-36 VDC I/O Module 4DI+8DO+3AI via Modbus protocol.
KTA-224 can now be powered 6.5-36 VDC, therefore KTB-224 has been discontinued.
KTA-224 can now be powered 6.5-36VDC, therefore KTB-224 has been discontinued.
The KTA-224 is a Modbus Slave I/O module for interfacing to any PLC or PC using the Modbus protocol. It behaves as a Modbus Slave and Relays, Inputs and Outputs are controlled by writing to and reading from the Coils and Holding Registers. It can be used for many applications such as controlling lights and sprinkler systems, reading sensors and monitoring switches and other digital signals, or even for industrial control.
The module can connect to a standard RS-485 2-wire half duplex network or to a computer via USB. When connected via USB, the module acts as a USB to RS-485 converter and multiple IO units (or other Modbus devices) can be connected to the RS-485 bus. USB drivers are available for Windows, Mac and Linux.
The user can save a set of output statuses to be loaded when the unit is powered up or reset. A watchdog timer can be configured to reset the unit after a user-definable number of seconds since the last communication from a Modbus master.

- Power Supply: 6.5 to 36 VDC
- Power Consumption: 500mA
- 4 x Opto-Isolated Inputs: with counters, 0 to 30V
- 3 x Analog Inputs: 10 bit resolution, jumper-selectable for 0 to 5 V or 0 to 20 mA
- 8 x Relay Outputs: SPDT, rated to 5A, 250VAC / 30VDC
- Protocol: Modbus RTU via RS-485 or USB (virtual serial port)
- 1200 to 38400 Baud Modbus Slave Device
- Can be used as a USB to RS-485 converter
- Watchdog Timer resets the unit when communication from the network master is lost
- Operating temperature: -20°C to 70°C
- Connections via Pluggable Screw Terminals
- Dimension: 140L x 110W x 36H (mm)
Dispatch
In-stock orders are dispatched within 2 business days.
Shipping options
We deliver across Australia and internationally by any of the following methods:
- Australia Post Express
- Australia Post Parcel Post
- DHL
- FedEx (only international)
- Freight account. We'll email packaging dimensions when the shipment is ready to be book.
*Transit times vary depending on the shipping method and destination.
Store Pickup - Carrum Downs, Victoria, 3201
Order before 11am to collect after 2pm the same day. Mon–Fri, 9am–5pm, excludes public holidays.
RETURNS
How to return an item Contact us before sending anything back. Email info@oceancontrols.com.au or call +61 3 9708 2390. We'll confirm eligibility and guide you to the return process.
Return window 14 days from dispatch date.
Condition required Items must be unused and in original packaging, including all documentation and manuals.
Restocking fee A 20% restocking fee applies to all accepted returns. Return shipping costs are the customer's responsibility.
Non-returnable items
- Custom-made or specially imported products
- Software licences (some software have trial versions available)
- Items not in original, as-new condition
WARRANTY
How to make a warranty claim Before returning anything, please contact us. Our engineers can often resolve the issue remotely. If a return is required, our team will provide you with a warranty form to include with the goods.
What's covered Defects in materials and workmanship under normal use and correct installation.
What's not covered The warranty does not cover damage or failures caused by factors outside our control, including incorrect installation, unauthorised alterations or modifications, or any installation or use not recommended by the manufacturer.
Standard warranty All products carry a 12-month warranty from the date of purchase unless stated otherwise.
Extended warranty
- Labjack: 5 Years
- Atop: 5 Years
- MeanWell: 3 Years
- Teracom: 3 Years
- Novus: 3 Years













