Modbus I/O Module 8AI+8DO (8-28VDC)

Modbus I/O Module 8AI+8DO (8-28VDC)

SKU: KTA-226

USB and RS-485 Modbus IO slave with 8 relays and 8 analog inputs. 8~28V version.

KTA-226 can now be powered 8-28VDC, therefore KTB-226 has been discountinued.

Ocean Controls
  • Manufacturer: Ocean Controls
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KTA-226 can now be powered 8-28VDC, therefore KTB-226 has been discountinued.

The KTA-226 is a Modbus Slave IO module for interfacing to any PLC or PC using the Modbus RTU 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 industrial control.

The module can connect to a standard RS485 2-wire half-duplex network or a computer via USB. When connected via USB, the module acts as a USB to RS485 converter and multiple IO units (or other Modbus devices) can be connected to the RS485 bus. USB drivers are available for Windows, Mac and Linux.

8 SPDT (changeover) relays can be operated as coils or with a pulse timer. The pulse timer switches the coil on for a specified number of milliseconds before automatically resetting it.

The 8 analog inputs are jumper-selectable for 0-5V or 0-20mA (including 4-20mA) input. 10 bit precision is presented on all channels.

The user can save a set of relay and timer 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.

All configuration parameters are available via Modbus. A small utility has been written which allows testing and configuration of serial parameters


  • Power Supply: 8 - 28VDC
  • Current Consumption: 500mA
  • Inputs: 8 x Analog Inputs (10 bit) 0-5V or 0-20mA Analog Inputs, Jumper Selectable
  • Outputs: 8 x Relay Outputs (5A, 250VAC / 30VDC)
  • Protocol: Modbus RTU
  • USB Virtual Serial Port or RS485 Input
  • Acts as a USB to RS485 converter
  • Easily connect multiple units far apart by RS485
  • Operating Temperature: -20 to 80°C
  • Connections via Pluggable Screw Terminals
  • Dimensions: 140 x 110 x 36 (mm)
    • SKU
    • Weight
      0.35 kg
    • Dimensions (L x W x H)
      25 x 15 x 4 cm

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Our standard warranty period is 12 months from the date of purchase unless stated otherwise.

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Labjack Products: 5 Years
Atop Products: 3 Years
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Warranty is subject to us being satisfied that a defect was caused by defective workmanship or materials and was not caused by or was not substantially contributed to by other factors beyond our control including incorrect installation, alterations or modifications of the product not recommended by the manufacturer.

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If you are dissatisfied with our goods you may return them within 14 days of the dispatch date. Contact us for an authorisation and we will refund your purchase less shipping costs and restocking fees. All returned goods MUST be in AS NEW condition including ALL PACKAGING and DOCUMENTATION / MANUALS etc.

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  • The product returned will attract a 20% restocking fee.
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  • Non standard, custom made or a specially manufactured or imported products are not returnable.
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