Trio Datacom Pty Ltd ER450-XXF01 Manuale Utente

Page 31

E Series Data Radio – User Manual

Part E – Getting Started - EB450

Digital Inputs and Outputs

The EB450 provides a facility for two channels of digital user inputs

and outputs (Digital User I/O). Information on how to control and

monitor this I/O using TVIEW+ Diagnostics can be found in Part J

- TVIEW+ Management Suite - Remote Diagnostics & Network

Controller.
All user I/O is optocoupled for isolation between the EB450 and

uses equipment. When using the I/O facility the I/O electrical

characteristics and ratings must be observed. Failure to observe

these ratings may result in equipment damage.

Inputs

Two User Inputs are available. They have identical interface

characteristics. Each input has an internal resistance of 470 Ohms.

Some form of switching contact (ie: switch, relay) is normally used

to change the state of the input. Both an isolated and non-isolated

input conﬁguration is possible.

Typical Radio Setup

TVIEW+ Diagnostics will recognise an input as being ON when the

switch is closed. If the switch is open (or not connected) TVIEW+

diagnostics will recognise the inputs as being OFF.

Outputs

Two User Outputs (Open Collector) are available. They have

identical interface characteristics. The maximum current allowed

through each output is 20ma. External resistors must be used keep

the current below this value.
Each output has an internal resistance of 100 Ohms.Ohms law can

be used to calculate the resistance required for a speciﬁc voltage

(keeping the current below 20mA). Nominally 1k Ohm is used for a

+13v8 supply and 330 Ohms for a +5v supply.
When the OUTPUT is OFF, V = Vs. No current will ﬂow when

output is off.
When the OUTPUT is ON, V = nominally 2.3 volts . Current is set

by resistor.