---
title: "General I/O port"
canonical: "https://docs.cuesystem.com/space/PRODUCTS/292388929/General%20I%2FO%20port"
format: markdown
---
The General I/O port provides analog input as well as digital output. Each General I/O port can be used either as input or as output.

**Connector pinout**

One 5-pin 3.5 mm connector for **4 ports** with the common ground is used.

| 5-pin 3.5 mm | Pin | Description |
| --- | --- | --- |
| ![image](media://c2dcbf39-9f82-49a0-b953-0e436eb293b9) | 1 S | I/O 1 - signal |
| 2 S | I/O 2 - signal |
| 3 S | I/O 3 - signal |
| 4 S | I/O 4 - signal |
| G | Common ground |

**Schematic diagram**

![image](media://925e6a25-5be4-48a9-a1db-44ad0ede5eb0)

# Analog input

For analog input usage, the output has to be in open status and a pull-up resistor can be used. 

**Parameters **of analog input are as follows:

- Analog input 0 ÷ 5 V
- Maximum input voltage 5 V
- Input resistance 66 kΩ
- A/D converter 10-bit (i.e. 1024 levels)
- Programmable 5 V / 680 Ω pull-up can be switched on and off for each I/O independently. I/O voltage with a pull-up on is approx. +4.3 VDC, because the protection diode is connected in series (0.7 V dropdown).

# Digital output

For digital output, the open collector switch is used and the pull-up resistor can be switched on. 

**Parameters** of digital output are as follows:

- Digital open collector output
- Max. 80 mA sink from maximum 24 VDC
- Output voltage for closed output switch is approx. 0.6 V.
- Programmable 5 V / 680 Ω pull-up can be switched on and off for each I/O independently. I/O voltage with pull-up on is approx. +4.3 VDC, because the protection diode is connected in series (0.7 V dropdown).