AN43: Remote relay and water leak detection with HWg-WLD
HWg-WLD – LAN water flood detector can detect water leaks but does not directly feature relay outputs. This Application Note shows how to signal leaks using remote relay outputs (Damocles 1208).
- Four HWg-WLD water leak detectors are placed at various locations in a building.
- Some of them are powered over the Ethernet (PoE) using CAT5 cable.
- The Damocles 1208 unit is located anywhere in the building where flood needs to be signaled.
- All four HWg-WLD water flood detectors are monitored over SNMP independently of the relay outputs.
- In the HWg-WLD web interface, select a “Damocles” remote device.
- The “Remote ID” value is the output to be activated.
Use 150 + output number = e.g. "152" to control Digital Output 2.
- Each HWg-WLD detector must control a different output.
Username and Password must allow write access to the remote device.
- Remote outputs are controlled using XML.
The remote output is set every time the status of the sensing cable changes, and periodically updated every 10s in order to recover after remote device power failures.
- To control O1, set Remote ID = 151 at the source device.
- The output must be configured in manual mode.
- Is it necessary to keep some software running in order to control relays over IP?
No, remote relay control works in the Box-2-Box mode, no software is needed.
Any Poseidon or Damocles product can be used as the remote relay output. HWg-WLD periodically (10s) sets the state of the selected output using XML.
- When is the water leak alert sent to the remote relay? Only upon activation?
No, this is a robust system. Box-2-Box mode updates the information periodically (every 10s by default).
- Can I connect several HWg-WLD to the same Damocles unit with relay outputs? Yes, but please use only one HWg-WLD per Digital Output (DO). Thus, in a typical application, 8 HWg-WLD units are linked with one Damocles 1208 unit with 8 DO. Each output signals a water leak at one particular zone.