RDG-24 Remote 24-Channel Digital I/O Pod

24 programmable digital I/O lines with isolated RS-485, counters, and pulse outputs

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Features

  • 24 remote digital I/O lines, programmable by bit, byte, or 24-bit word
  • Opto-isolated RS-485 serial interface
  • Inputs and open-collector outputs compatible with voltages up to 50 VDC
  • 350 mA maximum sink current per output, with a 650 mA maximum per six-bit group
  • 16-bit input event counters and per-input change-of-state detection
  • Programmable input sampling from 14 Hz to 1 kHz and output pulses from 7 Hz to 500 Hz
  • Protective steel enclosure and on-board watchdog
  • Designed and manufactured in the USA
Last updated on November 5, 2026, 8:48 am

$225.00

In Stock
$225.00
24-channel remote digital I/O pod, RS-485
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24-channel remote digital I/O pod, Wireless host-connection package
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24-channel remote digital I/O pod, USB host-connection package
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24-channel remote digital I/O pod, RS-232 host-connection package
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24-channel remote digital I/O pod, Ethernet host-connection package
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Description

RDG-24 is an intelligent remote digital I/O unit with 24 programmable lines and an opto-isolated RS-485 interface. A protective steel enclosure supports installation near field signals, while software controls the direction and state of individual bits, 8-bit bytes, or the complete 24-bit word.

Inputs accept signals up to 50 VDC. Each input supports a 16-bit software event counter with selectable rising- or falling-edge counting, plus an individually enabled change-of-state flag that can be read through the serial port. The input sampling rate is programmable from 14 Hz to 1 kHz.

Open-collector outputs support latched levels, timed pulses, or free-running square waves from 7 Hz to 500 Hz. Each output can sink up to 350 mA, subject to a combined 650 mA maximum for each group of six outputs. Outputs support external voltages up to 50 VDC and include inductive suppression diodes.

An on-board 8031 microcontroller, 8K of RAM, and 8K of EEPROM support local processing and data retention for later retrieval by the host. A watchdog resets the unit if the processor stops responding or the supply voltage falls below 4.75 VDC. An optional 32K EEPROM configuration is available.

Standard half-duplex operation requires no switch settings. Jumpers select two-wire or four-wire communication and can bypass the serial-interface opto-isolators when the application requires it. Packaged wireless, USB, RS-232, and Ethernet connectivity versions are also offered.

Modified-COTS (MCOTS) Customization

ACCES can tailor any standard product to your precise requirements — electrical, mechanical, firmware, environmental, or connector-level. Common MCOTS options include alternate I/O ranges, isolation enhancements, firmware changes, private labeling, conformal coating, extended temperature operation, ruggedized enclosures, and military-grade components. If this product is close but not a perfect fit, our engineering team can deliver a rapid-turn MCOTS variant with minimal NRE and dependable, Made-in-USA quality.

Digital Inputs

Channels Up to 24, configurable individually, by 8-bit byte, or as a 24-bit word
Input sample rate Software programmable from 14 Hz to 1 kHz
Event counters 16-bit software counter per input; rising- or falling-edge counting up to 65,535 transitions; read and reset commands
Change-of-state detection Individually enabled input flags, readable through the serial port
Logic low −0.5 to +0.8 VDC
Logic high +2.0 to +50.0 VDC
Low-level input current 450 µA maximum

Digital Outputs

Channels Up to 24, configurable individually, by 8-bit byte, or as a 24-bit word
Output modes Latched level, pulse, or free-running square wave
Pulse rate Software programmable from 7 Hz to 500 Hz
Output type Open collector with an inductive suppression diode in each circuit
Maximum sink current 350 mA per output; 650 mA combined maximum per six-bit group
Current-limit groups Bits 0–5, 6–11, 12–17, and 18–23
Voltage compliance Up to 50 VDC with a user-supplied voltage
Internal pull-up 10 kΩ to +5 VDC when no external voltage is supplied

Processing and Interface

Host interface Opto-isolated RS-485; jumper-selectable two-wire or four-wire operation
Processor 8031 microcontroller
Memory 8K × 8 RAM and 8K × 8 EEPROM; 32K × 8 EEPROM option
Watchdog Processor watchdog and reset below a 4.75 VDC supply level
Enclosure Protective steel enclosure, 8.5 × 5.25 × 2 inches; CE-marked configurations use a NEMA 4 enclosure

Power and Environmental

Serial-interface power 7.5 to 25 VDC at 40 mA for the opto-isolated section
Local power 7.5 to 16 VDC at 150 mA
Operating temperature 0 to 65 °C; optional −40 to +80 °C configuration
Temperature derating Maximum operating temperature depends on the applied power-supply voltage
Storage temperature −50 to +120 °C
Humidity 5% to 95% RH, non-condensing

Select the standard RS-485 model or a packaged host-connectivity version. The USB, RS-232, Ethernet, and wireless versions use connectivity hardware with the remote pod. Contact ACCES for configuration, pricing, and availability of packaged versions.

Call for Pricing

  • WM-RDG-24 — 24-channel remote digital I/O pod, Wireless host-connection package
  • U-RDG-24 — 24-channel remote digital I/O pod, USB host-connection package
  • S-RDG-24 — 24-channel remote digital I/O pod, RS-232 host-connection package
  • E-RDG-24 — 24-channel remote digital I/O pod, Ethernet host-connection package
ModelDescriptionPrice (USD)
RDG-24

24-channel remote digital I/O pod, RS-485

$225.00
WM-RDG-24

24-channel remote digital I/O pod, Wireless host-connection package

Call for price
U-RDG-24

24-channel remote digital I/O pod, USB host-connection package

Call for price
S-RDG-24

24-channel remote digital I/O pod, RS-232 host-connection package

Call for price
E-RDG-24

24-channel remote digital I/O pod, Ethernet host-connection package

Call for price