Interface Modbus devices with Cytech Comfort

The UCM/Modbus allows Modbus devices to be interfaced to Cytech’s Comfort Automation/Security System, Environmental Monitoring System and Logic Engine products. The UCM/Modbus has the unique ability to be configured either as a Modbus Master or Slave. Master mode is for Comfort to control other Modbus Slave products, and Slave mode is for a Modbus Master to control Comfort.

The UCM/Modbus can work with other Comfort modules including Intelligent Remote Input/Output Modules (IRIO), Multi-Sensor Modules (MSM01), Hotel I/O (HIO) as well as 3rd party systems on the Comfort Bus including C-Bus and KNX, allowing Modbus to be integrated with other 3rd party products.

Product Photos

with RS485 Interface
with RS485 Interface
with Ethernet Interface
with Ethernet Interface


IRIO TWS comfigurator screen


The UCM/Modbus is programmed using the free Comfigurator Software tool. (Requires UCM Universal Communications Module).

UCM/Modbus Modes

Modbus Master Mode

Used to monitor and Control Modbus Slaves. Multiple Slave Ids can be addressed.

256 Modbus Registers can be mapped to Comfort Registers and supports Discrete Inputs, Coils, Input Registers, Holding Registers.

Modbus Registers can be mapped to Comfort Register types: Counters, Sensors, Flags, Outputs, Inputs allowing values to be processed, converted or sent to other systems.

Comfort Alarm conditions can be mapped to Modbus Registers.

Modbus slave Mode

Slave Mode is used for 3rd party software to control Comfort.

For Modbus Slave, supported Function codes are; Read Discrete Inputs, Read Coils, Read Input Registers, Read Holding Registers, Write Single Coil, Write Single Holding Register.

Modbus Discrete Inputs are mapped to Zones/Inputs.

Modbus Coils are mapped to Comfort Outputs, Flags and Bypass Inputs.

Modbus Input Registers are mapped to Comfort Security conditions.

Modbus Holding Registers are mapped to Sensors and Keypad keys

Modbus Monitor Mode

Monitor Mode allows Modbus communications in both directions in Master and Slave Mode to be shown for testing purposes.

Functions & Features

  • Scheduling by Day of Week or Times of day
  • Conditional Logic Processing based on Modbus Register values
  • Activate Comfort Outputs or Relays by Modbus: On/Off/Pulsed Outpts
  • Comfort Inputs can be linked to Modbus Register Values
  • Control/Monitor by Cytech Android/iOS app
  • Alarm Conditions can be mapped to Modbus Registers
  • Interface with IRIO01 analog Input/Output Modules for industrial applications
    • Interface to MSM01 Multi-Sensor modules with built-in Temperature and Humidity Sensors, and Water Leakage
    • Inputs for Server Room Monitoring

Time programs

Time programs can be scheduled to switch any device on or off or change temperature of aircons based on time of day and different days of week.

External Interfaces

In addition to Modbus, interfacing to KNX and C-Bus Automation systems via external UCMs (Universal Communications Module) is also available.

App Control

App control

Free apps are available for iOS and Android to control and see the status of the conected lighting, aircons, blinds and other appliances. The UCM/Logic ethernet interface should be connected to the router in the house.


IRIO Connections

The UCM/Modbus can be connected to the same Cytech RS485 network as KNX, C-Bus, Modbus and other 3rd party interfaces . A Comfort CM9001, UCM/Logic, KNX/Logic or LGX01 can act as a central controller on the bus. The LGX Logic Engine has 8 Inputs and Outputs. UCM/Logic is a low cost controller with no Inputs and Outputs. CM9001 is an integrated Alarm and Automation system with 8 to 96 Zones.


  • Low Power Microcontroller with Flash memory for firmware and configuration settings.
  • Power Supply: 12V DC 30 mA, from CM9001 Controller
  • Operates as Modbus Master or Slave (selectable)
  • Physical Interfaces Modbus/RTU (for RS485) Modbus/TCP
    • Modbus/RTU Baud rates: 2400, 4800, 9600, 19200 38400, 57600. Parity Odd/Even/None
    • Comfort CM9001, UCM/Logic, LGX01 Logic Engine. KNX/Logic can act as the central controller for UCM/Modbus.
  • For Modbus Master Mode: 256 Modbus Slave ID/Modbus Addresses
  • Up to 8 UCMs (KNX, Modbus, C-Bus, Universal) in 1 system

More information