Digital Input/Output; Modbus I/O Transfer - Honeywell XYR 400E User Manual

Wireless ethernet modem

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3.14

The functionality of the shared Digital Input/Output pin may be configured via the "I/O Transfer"

internal webpage. As this pin is shared, the Digital Input status will be ON when the Digital Output

is set ON.

The Digital I/O channel can be transferred to/from another device using Modbus (see section "3.15

Modbus I/O Transfer" below) or it can be configured to provide status of the module

communications. If the XYR 400E disassociates from another unit (that is, there is no wireless

link), you can configure the digital output to turn ON (set) or OFF (drop).

3.15

The XYR 400E provides Modbus TCP Client and Modbus TCP Server functionality for I/O

transfer. 5000 x 16bit general purpose registers are provided for Modbus (including the onboard

Digital Input/Output) and are shared for both Client and Server. Modbus TCP Client (Master) and

Modbus TCP Server (Slave) are both supported simultaneously, and when combined with the built

in Modbus TCP to RTU Gateway the XYR 400E can transfer I/O to/from almost any combination

of Modbus TCP or RTU devices.

The layout of the XYR 400E I/O Registers is summarized in the table below. Each register is

internally saved as a 16 bit value. A Modbus transaction may access the entire 16 bit value of any

The main use for the general purpose I/O registers is for intermediate storage, i.e. when transferring

I/O from one Modbus Slave device to another. Also provided is the status of the onboard digital I/O,

as well as the status of the wireless link. The 16 bit status register contains the value FFFF(hex) for

ON and 0000(hex) for OFF. Inverted status registers are also provided where the registers contain

0000(hex) for ON and FFFF(hex) for OFF.

Digital Input/Output

XYR400E Ethernet Modem

Version 1

5/1/08

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