Build Modbus Threshold Slack Alert

Build a factory alert workflow: read a temperature register from a PLC, evaluate warning/critical thresholds, and post to a Slack channel when limits are exceeded.

What this template does

1. Every 30 Seconds — cron trigger (template uses */1 * * * *; tune as needed).
2. Read Temperature Register — single holding register from the PLC.
3. Check Threshold — critical high 80°C, warn high 60°C.
4. Slack Alert — message to #factory-alerts.

Step 1 — Load the template

1. Studio → Templates → search Modbus Threshold Slack.
2. Load template #131.

Step 2 — PLC register

1. Set Modbus Host, Port (502), and Start address for your temperature register.
2. Confirm fieldPath in the threshold node matches Modbus output (values.0 by default).

Step 3 — Thresholds

1. Open Check Threshold. Set Critical high and Warn high for your process.
2. Add a Condition before Slack if you only want alerts on critical, not every poll.

Step 4 — Slack

1. Paste your Slack Webhook URL in the Slack node (or {{$var.slackWebhook}}).
2. Customize the message template with {{values}} and {{zone}} from threshold output.

Step 5 — Run on-prem

1. Activate on an on-prem Studio instance or exported runtime near the PLC.
2. Simulate high register values in Dry Run if Modbus is unavailable.
3. Verify Slack messages and run history.

Related tutorials

• Modbus PLC → InfluxDB Logger — continuous telemetry.
• Approved Device Command — safety gates for device actions.
• Runtime Monitoring — agent dashboard and heartbeats.