Monitor devices

Know when a product or Gateway needs attention: offline, low battery, jammed, or failing commands. This guide shows what Parklio tells you, what it doesn't, and how to combine realtime events with REST checks.

Prerequisites

• An API token on a server; see Authentication.
• A realtime connection; see Connecting.

What you can watch

Signal	Where	Pushed in realtime?
Product state, battery_status, rssi, product_error	lot_change (no event_id), and the product in REST	Yes, while a Gateway sees the product
Product online or offline	status in lot_change, and on GET /v2/products	Yes
Products with an error	GET /v2/products/errors	(via lot_change)
Gateway online or offline	gateway_status, and status on GET /v2/gateways	Yes, for Gateways assigned to a lot
Failed commands	gateway_error	Yes

1. Watch status updates

While a Gateway sees a product, it reports it regularly, and each report arrives as a lot_change without event_id, twice, whether or not anything changed. When no Gateway sees the product any more, or its Gateway disconnects, a lot_change with status offline follows. Keep the last value per product and alert on changes; see Deduplicate status updates.

watch-products.ts

// alert() and resolve() stand for your alerting.
const last = new Map<number, { online: boolean; errorCode: string | null; low: boolean }>();

socket.on('lot_change', (raw: string) => {
  const { event_id, data } = JSON.parse(raw);
  if (event_id) return; // command results are handled elsewhere

  const online = data.status === 'online';
  const errorCode: string | null = data.product_error?.error_code ?? null;
  const low = isLowBattery(data.battery_status);
  const prev = last.get(data.id);
  last.set(data.id, { online, errorCode, low });

  if (!online && prev?.online) alert(data, 'offline');
  if (online && prev?.online === false) resolve(data, 'back online');
  if (errorCode && errorCode !== prev?.errorCode) alert(data, `error flags ${errorCode}`, data.product_error);
  if (!errorCode && prev?.errorCode) resolve(data, 'error cleared');
  if (low && !prev?.low) alert(data, `battery at ${data.battery_status}%`);
});

function isLowBattery(value: unknown) {
  // Only barriers report a battery level. 0–100 is percent; above 100 means grid power.
  return typeof value === 'number' && value <= 20;
}

Online and offline

status in lot_change is online or offline. battery_status and rssi are null while a product is offline.

Don't alert on a single offline event. Products can show offline briefly, for example while their Gateway reconnects or during Parklio maintenance, until a Gateway sees them again. Alert when a product hasn't come back online within a few minutes.

Error flags

product_error is present while the device reports at least one problem, and gone when none is left. Each flag is 0 or 1:

Flag	Products	Suggested action
jammed	Barrier	Send someone on site.
sensor_dirty	Barrier	Clean the car sensor.
battery_empty	Barrier	Replace or charge the battery.
pin_broken	Barrier	See the product's manual.
rtcc_invalid	All	The device's clock isn't set; time-limited credentials fail until it is. Parklio sets it when a Gateway sees the device.
master_key_not_set	All	See the product's manual.

For a list of every product that currently has an error, call GET /v2/products/errors. It accepts the same filters as the products list, such as lot_id.

Battery

Only barriers report battery_status. It's a percentage from 0 to 100; Parklio sets battery_empty below 15%. Values above 100 mean the barrier runs on grid power, not a battery level. Alert somewhere around 20% to leave time to act.

2. Watch Gateways

gateway_status tells you when a Gateway assigned to a lot connects or disconnects. It identifies the Gateway by uuid; match it with the uuid field of GET /v2/gateways.

watch-gateways.ts

socket.on('gateway_status', (raw: string) => {
  const { uuid, status } = JSON.parse(raw);
  if (status === 'offline') alert({ uuid }, 'Gateway offline');
});

When a Gateway goes offline, the products only it could see become offline too, and commands to them fail with 704. To check all Gateways at once, for example after a reconnect:

Gateways that are offline

curl -s "https://api.parklio.com/v2/gateways?filter=status:eq:offline" \
  -H "Authorization: Bearer $PARKLIO_API_TOKEN"

3. Watch failed commands

A run of gateway_error events for the same product, especially 5 (jammed), 7 (sensor dirty) or repeated "Timeout", is often the first sign of trouble on site. Count them per product and alert above a threshold. See Remote control.

Alerting ideas

Alert	Rule of thumb
Product offline	lot_change with status offline, not back within a few minutes.
Gateway offline	gateway_status offline, not back within a few minutes.
Low battery	Barrier battery_status ≤ 20.
Needs service	jammed or sensor_dirty set.
Commands failing	Three gateway_errors for one product within an hour.

Verify it worked

1. Your monitor logs a lot_change without event_id for each product within a few minutes of starting.
2. Unplug a Gateway (or switch off its network): you get gateway_status with offline, and a lot_change with status offline for each of its products.
3. Plug it back in: gateway_status online, and the products' lot_change events resume.

Common errors

Symptom	Cause	Fix
No lot_change for a product at all	No Gateway sees it, or it's on a lot your token can't see.	Check its status and lot_id; see Troubleshooting.
Duplicate alerts	Status updates repeat, and each is sent twice.	Alert on changes only.
battery_status is null	The product is offline, or isn't a barrier.	Expected.
battery_status above 100	The barrier is on grid power.	Not a battery level; ignore.
gateway_status for an unknown uuid	The Gateway isn't in your cached list.	Re-read GET /v2/gateways.
Missed changes after a disconnect	No replay.	Re-read GET /v2/products after every reconnect.

Next

• Remote control
• Events