Vigilohm IM20 and IM400 insulation monitors are supported natively in spaceLYnk 1.2.1 and homeLYnk 1.5.1, so the gateway firmware is the first reading to take when a monitor is missing or silent. Facility Hero can sit on top of that same gateway for remote access to the data. Work the checks below in order; each one either clears a branch or sends you to the next.
Read the gateway firmware version first
Open the gateway's web interface and read the installed firmware version before you touch wiring or tags. Native support is documented for spaceLYnk 1.2.1 and homeLYnk 1.5.1, so those are the reference releases.
- Firmware at or above the native-support release: the driver is present. Go to the model check.
- Firmware older than the release above: the native monitor support is not the baseline you are running. Plan the update (see the repair procedure). Do not build a workaround on old firmware.
Wrong fix first: hand-building a register map or custom tags for the monitor on an old gateway. It appears to work, then breaks alarm handling, and it has to be removed after the update anyway. The firmware package for spaceLYnk v1.2.1 is listed in the EcoXpert catalogue.
Confirm the monitor is an IM20 or an IM400
Read the nameplate or the device front label. The native support statement covers the IM20 and the IM400 only.
| Nameplate reads | Meaning | Next check |
|---|---|---|
| IM20 | Covered by native support | Measurement check |
| IM400 | Covered by native support | Measurement check |
| Any other Vigilohm reference | Not covered by the native statement; check that model's documentation for gateway support | Stop here; do not force it in |
An insulation monitor watches the resistance between the live conductors and earth on an isolated-neutral (IT) system and raises an alarm when it falls below a threshold. That threshold is stored in the monitor. The gateway only retrieves measurements and alarms, so nothing set in the gateway changes what the monitor considers a fault.
Check that measurements arrive before chasing alarms
Compare the insulation value on the monitor's own display with the value the gateway shows for the same device.
- Note the local reading and time.
- Read the gateway value for that device.
- Compare.
| Result | Mechanism | Next |
|---|---|---|
| Values match within normal drift | Driver and link work | Alarm check |
| Device absent or value frozen or invalid | Communication path down or mismatched | Verify the link settings below |
| Value present but wrong scale or unit | Wrong device type selected in the gateway | Re-select IM20 or IM400 to match the nameplate |
For a missing device, check the physical link in this order: cable and connector seated, terminations, then the device address and line settings on both ends. Read the exact interface and setting ranges from the IM20 or IM400 manual; they are not repeated here because they depend on how your unit is connected. Two devices on one link sharing an address is a classic cause of intermittent or frozen values.
Check alarm states against the monitor's own display
Measurements arriving does not prove alarms are arriving. Compare the monitor's alarm indication with what the gateway reports.
- Both show alarm: the path is healthy. The problem is a real insulation fault; locate it on the installation.
- Monitor shows alarm, gateway does not: alarm retrieval or notification setup is the fault. Re-check the device type selection and the gateway's alarm configuration.
- Gateway shows alarm, monitor does not: stale data or a link that dropped after the last valid read. Go back to the measurement check.
Wrong fixes to reject: raising the alarm threshold on the monitor to silence a nuisance alarm, or acknowledging it at the gateway and moving on. A falling insulation value is a physical condition on the circuit. Silencing the indication leaves the fault in place and removes your early warning of a first earth fault.
Restore the link: temporary hold and permanent repair
Temporary hold (keep production running):
- Read the insulation value and alarm state on the monitor's own display each shift and log it by hand.
- Leave the monitor thresholds unchanged.
Permanent repair, firmware below the native-support release:
- Export or record the current gateway configuration so it can be restored.
- Download the firmware package from the EcoXpert catalogue page for your gateway (spaceLYnk v1.2.1 is the referenced release).
- Schedule the update; the gateway is offline for the monitoring and remote functions during the process. Keep the manual logging active.
- Apply the firmware through the gateway's own update function and let it finish without power interruption.
- Re-select the device as IM20 or IM400 and re-enter the address and line settings from the manual.
Stop rule: if the update fails or the gateway does not come back, stop and contact official support with the firmware version and the device model. Do not repeat power cycles.
Verify the fix with matching values and a live alarm path
- Confirm the gateway firmware version now reads the target release or higher.
- Confirm the gateway insulation value matches the monitor's display on two readings taken a few minutes apart.
- Confirm the alarm state agrees on both. If a maintenance window allows, trigger a controlled alarm using the test procedure in the IM20 or IM400 manual and confirm it appears at the gateway, then clears when the test ends.
- If Facility Hero is used, confirm the same values appear there only after the local gateway check passes. A gap in the upstream service with correct local values points to the gateway's connection to that service, not the monitor.
FAQ
Why does my gateway not list the Vigilohm IM20 or IM400?
The most likely cause is gateway firmware older than the release with native support: spaceLYnk 1.2.1 or homeLYnk 1.5.1. Read the installed version in the web interface and update before creating any custom tags.
Why does the gateway show insulation values but no alarm?
Alarm thresholds live in the monitor, so compare the monitor's own alarm indication with the gateway. If the monitor alarms and the gateway does not, re-check the device type selection and the gateway's alarm configuration.
Why does an insulation alarm clear at the gateway and come back?
Acknowledging at the gateway does not change the measured insulation resistance. The monitor keeps measuring, and the alarm returns while the fault is still on the circuit, so locate and clear the physical earth leakage.
When should I stop troubleshooting and call official support?
Stop when the firmware update fails, when the gateway does not restart afterward, or when the device model is not an IM20 or IM400 and native support is unconfirmed. Contact Schneider Electric support with the gateway model and firmware version, the monitor nameplate, and a description of what the local display shows versus the gateway. Keep the manual shift logging running until the link is verified.