IO Command — I/O Status Query

The IO command returns the current state of digital inputs, digital outputs (XP), ignition sensor (IGN), and system voltages.

What is it for?

🔌 Quick diagnostics — View all I/O status in one command
🚗 Ignition status — Check if vehicle is running
📥 Digital inputs — Query door sensors, panic button, etc.
📤 Digital outputs — Confirm relay and actuator status
🔋 Voltages — Monitor main and backup battery

Syntax

Response

RIO;IGN{0|1};IN{bit6..bit0};XP{bit2..bit0};V{dV};VBU{cV}

Examples

Vehicle with ignition on

>QIO<
>RIO;IGN1;IN1111110;XP010;V127;VBU420;ID=1234;*55<

Decoding:

Vehicle turned off

>QIO<
>RIO;IGN0;IN1111111;XP000;V125;VBU415;ID=1234;*3A<
// IGN OFF, all inputs open, outputs off

Interpretation:

- IGN: OFF
- IN: All open
- XP: All off
- V: 12.5 V
- VBU: 4.15 V

Alarm activated

>QIO<

Response:

>RIO;IGN0;IN1111101;XP001;V126;VBU418...

Interpretation:

• IN01=0 (door sensor activated)
• XP00=1 (siren activated)

IN Input Decoding

Inputs are reported in binary from MSB (bit 6) to LSB (bit 0):

Example: IN=1111110

• IN06-IN01: Open (1)
• IN00: Grounded (0)

XP Output Decoding

Outputs are reported in binary from MSB (bit 2) to LSB (bit 0):

Example: XP=010

• XP2: OFF (0)
• XP1: ON (1)
• XP0: OFF (0)

Voltage Values

Main Voltage (V)

Expressed in tenths of volt:

• V127 = 12.7 V
• V140 = 14.0 V (charging)
• V115 = 11.5 V (low battery)

Backup Voltage (VBU)

Expressed in hundredths of volt:

• VBU420 = 4.20 V (LiPo battery OK)
• VBU350 = 3.50 V (low battery)

Compatibility

See Also

• XP Command - Digital output control
• AIN Command - Analog inputs
• Event Engine - Input/output automation
• Trigger List - Available events