---
title: RLY8 - GPIO Board mk2
slug: hardware/rly8-gpio-board-mk2
docTags: 
createdAt: 2023-05-22T08:49:28.000Z
---

![](https://api.archbee.com/api/optimize/wP9peVc2bAVBPOh6IboCS/20AMf9DEyJ88HDhk-bQdA_rly8.png)

If you need more I/O than is available on your controller you can expand it with this RLY8IO expansion board. Eight additional relay outputs and eight opto-coupled inputs. This card is connected through the Modbus-RTU interface of the controller.

## Technical Specifications

- 2x RS485 interface: RS485, MODBUS compatible (cable length up to 20m)
  - 1x RS485 In for connection to the controller
  - 1x RS485 Out to daisy chain to additional RS485 devices
- 1x CPU5B Connection (connect to EXT-2 on CPU5B)
- 8x Relay outputs (up to 24V)
- 8x Optocoupler isolated inputs (works from 5-24V input voltage, 1 mA)
- Power supply: 24V DC
- Dimensions: 107x160mm
- Others: Firmware upgradable through the USB connection

## Board Overview

![](https://api.archbee.com/api/optimize/wP9peVc2bAVBPOh6IboCS/Ebsx7fZsHsT1-tFlCM1UF_image.png)