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ICON Controller Overview
ICON I/O Overview
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ICON I/O Overview


The ICON controller connects to a Power/Bus module for power and to convert the controller's RS232 interface to Modbus RS485 interfaces for interfacing Modbus I/O devices. The Power/Bus module also has a Dallas 1-wire bus interface for interfacing Dallas 1-wire I/O devices and sensors.

The ICON Modcombo I/O module provides 10 inputs and 8 outputs for interfacing sensors and controlling devices. Other Modbus devices from other manufacturers that support the Modbus RTU serial or TCP protocol are supported.

Modcombo                                                            Power/Bus          Controller

Power/Bus Module

The Power/Bus module accepts an unregulated input of nine to 24 VDC or VAC and generates regulated +5V for powering the ICON controller and other Modbus I/O devices. This module also has two RS485 Modbus interfaces, one isolated and one non-isolated and one Dallas Semiconductor 1-wire device interface bus.

There are two configurations for the Power/Bus module. The first configuration is used in conjunction with the ICON controller and converts the ICON controller's RS232 interface into two Modbus interfaces, a local non-isolated RS485 bus for Modbus I/O devices located next to the controller and an isolated RS485 Modbus to interface Modbus devices located up to 4000 feet from the controller.

The second configuration is designed for remote locations. In this configuration the Power/Bus module connects to the isolated RS485 Modbus and converts to a local RS485 Modbus for one or more Modbus I/O devices located with the remote Power/Bus module. It also supplies power to these I/O devices.

The system supports one local Power/Bus module with controller that can communicate with up to 31 remote Power/Bus modules. Total cable length is 4000 feet. Up to 254 Modbus I/O devices can theoretically be connected to this Modbus network. In reality throughput considerations limit the number to something much less.

Each Power/Bus module also contains a Dallas Semiconductor 1-wire device bus. This bus can support up to 127, 1-wire devices such as temperature probes with total bus lengths up to 1000 feet long. The 1-wire devices are controlled from Modbus registers written to and read from the Power/Bus module. Therefore, from a programmer's perspective, the Dallas 1-wire devices look like Modbus devices.

Modcombo I/O module

The Modcombo modules connect to the non-isolated Modbus from a Power/Bus module. This bus supplies +5V power to the unit along with the the RS485 Modbus signals. Each Modcombo board has the following specifications:

  • All 10 inputs can be selected for digital input
  • The first 8 inputs can be selected for analog input on a channel by channel basis
  • All 10 input channels can do event counting, slow speed on channels 1-8 (5HZ max) and high speed (10KHZ) on channels 9 and 10
  • Inputs 9 and 10 can also measure frequency
  • All 8 outputs are single pole relays than can switch up to 30VDC or 110VAC non-inductive loads up to three amps

 Interface Specifications for all Modbus devices  

  • Serial RTU Modbus (TCP Modbus is also supported but its operation is over the ethernet port) Baud rate of 9600 or 19200 switch selectable
  • Parity can be selected for none or odd.
  • Unit address of 1 to 255 switch selectable 
  • Supports Modbus commands 1, 2, 3, 4, 5, 6, 15 and 16

Last updated December 5,2012