RIO-28 I/Os

Terminal Strip Connections

RIO-28 devices connect to power and user signals via four green, screw-terminal connectors. Each pin on these connectors is labelled on the housing's overlay:

DO1, DO2, DO3, DO4, DO5, DO6, DO7, DO8

open collector, digital outputs; When the associated DO LED is lit, the output is pulled to ground. Each output is rated at 200mA max.

GND

ground; Negative DC power for the RIO device and electrical reference point for all inputs and outputs. All ground pins are tied together internally.

DI1, DI2, DI3, DI4, DI5, DI6, DI7, DI8

optically-isolated digital inputs; These inputs are pulled high internally, and suitable for connecting to most Form A or TTL outputs.

5V

5 Volt supply for user sensors; Maximum current load is 100mA.

AI7, AI6, AI5, AI4, AI3, AI2, AI1

analog inputs; Each input is capable of measuring a signal from 0 to 20mA. The module presents a 250Ω load on each input.

AO1, AO2, AO3, AO4

analog outputs; Each output is capable of driving from 4 to 20mA into a 250Ω load.

B

positive RS-485 signal

A

negative RS-485 signal

TXD

transmit data, from the RIO-28 to the user device

CTS

clear to send; a high signal indicates that the RIO-28 needs to send data

RXD

receive data, from the user device to the RIO-28

DTR

data terminal ready; used to place the radio into command mode

12V

positive DC power for the RIO device; Both pins are tied together internally.

Most installations do not require hardware handshaking.

Digital Inputs

Digital inputs should be driven to ground to signal "on".

Use a Debounce value of 75 for mechanical inputs and a Debounce value of 0 for digital inputs.

Digital Outputs

RIO-28 outputs are pulled to ground when "on". They can sink up to 200mA. Here is a typical configuration that uses the output to control a user load:

Analog Inputs

Analog inputs can sense a range of 0 to 20 mA. Here is a typical configuration that uses the analog input to monitor the current through a sensor.

Analog Outputs

Analog outputs can drive a range of 0 to 20 mA into a 250Ω load.