System Input

Applies to: IOcan · Standalone controller. What this means

Overview

A System Input exposes an internal value — something the device measures about itself rather than reads off a sensor wire. There is nothing to wire and no type-specific settings: the pin field acts as a selector for which value you get.

Battery voltage and ignition status are properties of how the device is powered — the IOcan pinout and the standalone controller pinout document the supply pins those readings come from.

The five selectable values

Selector Value Notes
1 Battery voltage The supply voltage at the device, in millivolts. Also used internally to inhibit the input watchdog below about 8 V.
2 5 V output measurement The sensor supply rail, in millivolts. The device raises its own faults if this leaves specification — see below.
3 Ignition status 1024 when KL15 is asserted, 0 when it is not.
4 Overcurrent alert The output stage's overcurrent alert line.
5 Overcurrent sense The output stage's overcurrent sense line.

Any other selector value produces no input at all.

The device already monitors the 5 V rail on its own: it raises a fault if the rail is shorted to ground, and another if it sits below about 4.75 V. Bringing the measurement in as a System Input is for logging and for your own logic — it does not enable the monitoring, which is always running.

Prerequisites

None. There is nothing to wire and no source input.

Add it in the app

  1. Add a new input and choose System Input as the type.
  2. Choose the pin / selector for the value you want.
  3. Name it after the value, so a reader of the configuration can tell which selector was chosen without looking it up.

Settings reference

This input has no type-specific settings. The value is chosen entirely by the selector.

Common settings

System Input uses the shared Name and Pin settings, where Pin is the selector rather than a physical pin. See Common IO settings.

Example — low-battery warning

  1. Type System Input, selector Battery voltage, name Battery V.
  2. Feed Battery V into a Compare Input with mode LessThan, value 11700 and deviation 200 — trips below 11.5 V and clears above 11.9 V.
  3. Leave the compare filter off so the warning stays on while the voltage is low.

Example — gating logic on ignition

Use selector Ignition status as an operand or a mux selector where something must only run with the key on. It reads as a plain boolean, so it works directly anywhere the 512 threshold applies — counter triggers, waveform triggers, RBC bits.

Troubleshooting

  • The input does not exist: the selector is outside 1–5.
  • Reads a different quantity than expected: the selector numbering is the table above — battery voltage and 5 V measurement are adjacent and easy to swap.
  • Battery voltage looks like a small number: it is in millivolts, so 14.4 V reads as about 14400, not 1024. It does not follow the full-scale convention.