What the PWR, COM and NET Lights Mean on a Solis Datalogger
The three labelled lights describe separate parts of the monitoring path. PWR is power, COM is logger-to-inverter communication, and NET is the connection to the Solis server. Reading them separately avoids assuming an inverter fault.
Scope and safety This guide is for the S2-WL-ST, S3-WiFi-ST, S4-WiFi-ST and S5-WiFi-ST models covered by Solis's current support article, including USB and four-pin versions. Indicator layouts and behaviour on older DLS-W, GPRS, LAN-only or other logger families may differ. Observe the label and lights only. Do not remove, rotate or reseat an installed logger, open the inverter or touch wiring. Solis says an installed logger should not be disconnected without prior permission from support.
The direct answer
Solis gives the following meanings for a solid indicator:
| Indicator | What a solid light confirms | What it does not prove by itself |
|---|---|---|
| PWR | The power indicator is active. | It does not prove the inverter is generating or that cloud data is current. |
| COM | The datalogger is communicating with the inverter. | It does not prove that the logger has reached the internet or Solis server. |
| NET | The datalogger has connected successfully to the server. | It does not prove that COM is healthy or that the inverter is producing power. |
Solis's current public support article does not assign a universal meaning to every colour and flash rhythm in the short indicator table. Do not turn an unfamiliar flashing pattern into a diagnosis. Record it, including the model and timing, and check the model-specific document or ask support.
Why there are three lights
Monitoring data travels through a chain:
- the datalogger needs power;
- it needs to communicate with the inverter;
- it needs a network route to the Solis server;
- SolisCloud then displays the uploaded information.
The indicators separate those links. A solid COM light with no confirmed NET connection points towards the network side, not automatically towards an inverter fault. Conversely, NET alone does not establish that fresh inverter data is reaching the logger.
This distinction matters because "offline in the app" and "not generating" are not the same report. A broadband outage, changed router password or weak Wi-Fi can interrupt monitoring while the electrical system requires an entirely separate assessment.
First identify the datalogger
Before interpreting anything, read the model from the logger label. The current Solis support page covers:
- S2-WL-ST;
- S3-WiFi-ST;
- S4-WiFi-ST;
- S5-WiFi-ST.
Solarboss currently lists the SOL-S2-WL-ST-USB, a two-in-one Wi-Fi and LAN logger intended for Solis inverters with a USB COM port. Its product page identifies LED status indicators for power, network and inverter communication.
Do not identify a logger from shape alone. USB, four-pin and older DLS products may need different instructions. Note the logger model separately.
How to read the lights without over-diagnosing
PWR: logger power status
PWR is the logger's power indicator. If it is active, move on to COM and NET rather than treating power as the whole answer.
If all indicators are off, Solis's network troubleshooting advises checking whether the inverter is powered and checking the connector or port condition. For a homeowner, that should remain a visual check. Look at the inverter's normal external display or indicators and note whether the logger appears loose or damaged. Do not remove it to test the port.
COM: logger-to-inverter communication
A solid COM indicator confirms a successful communication connection between the datalogger and inverter. If COM is not solid, the logger may be online as a network device but not receiving the expected inverter information.
Do not try to correct COM by twisting the logger body. Solis warns that doing so can loosen or damage the COM port. If the indicator does not settle after normal operation, photograph the external connector area and ask the installer or Solis support to check compatibility, seating and port condition.
NET: logger-to-server connection
A solid NET indicator confirms that the logger has connected to the server. If NET is not solid while PWR and COM appear healthy, focus first on the home-network history: a changed router, Wi-Fi name or password, broadband outage, weak signal, or router configuration.
The correct reconnection route depends on model. Solis currently uses Bluetooth configuration for S2-WL-ST and S5-WiFi-ST, and a browser configuration route for S3-WiFi-ST and S4-WiFi-ST. Do not borrow setup steps from a different generation.
Common combinations and the safest next step
These combinations are observations, not replacement fault codes:
PWR, COM and NET are all solid
The three monitored links appear established: logger power, inverter communication and server connection. Check whether the SolisCloud timestamp advances. If the platform remains stale, record the time and app screen before contacting support; do not alter inverter settings.
PWR and COM are active, but NET is not solid
The inverter communication link may be present, while connection to the Solis server is not confirmed. Check whether broadband is working and whether the router credentials recently changed. If reconnection is needed, follow the current Solis instructions for the exact logger model.
PWR is active, but COM is not solid
Power to the logger may be present, but successful communication with the inverter is not confirmed. This is not a reason to open the inverter or reseat the device. Record the exact model, all light states and any SolisCloud message, then ask the installer to confirm compatibility and the physical connection.
All lights are off
Look at the inverter's external indicators from a safe position. If the inverter also appears unpowered, treat that as an inverter or supply symptom and contact the installer. If the inverter looks operational but the logger remains completely dark, support may need to assess the logger, connector and port. Do not disconnect it yourself.
A light keeps flashing
Record which labelled light flashes, its colour and a ten-second video showing the rhythm. Solis's concise current indicator table only defines the solid COM and NET states and identifies PWR as power status. Use a model-specific document or support response for any more exact interpretation.
Safe homeowner checks
The following checks do not require opening equipment:
- Read the logger label. Record the complete model and serial, not just "Solis stick".
- Observe all three lights together. Note solid, off or flashing and the colour shown.
- Check the time. Compare the current time with the last update shown in SolisCloud.
- Check the home internet. Confirm another device can reach the internet through the same router.
- Recall recent changes. Note any replacement router, changed SSID, changed password, guest-network change or broadband outage.
- Keep the phone nearby. If using the approved configuration flow, work close to the inverter so a weak local connection is less likely.
- Wait briefly after a configuration change. Solis's Wi-Fi guide says to check the datalogger status and allow up to five minutes for an update before rechecking the password and setup.
Do not repeatedly press reset. Solis says a logger reset erases data and network settings. If reset is proposed, have the installer or Solis support confirm it for that exact model.
Stop and call your installer when
Escalate the issue when:
- the model label cannot be read or does not match the four families in this guide;
- all logger lights are off and the inverter also appears unpowered;
- COM will not become solid after a normal network setup;
- the logger is visibly loose, cracked, wet or damaged;
- the connector or inverter COM port needs inspection;
- the datalogger must be removed, reseated or replaced;
- the app requests installer access or changes to inverter settings;
- a monitoring problem is accompanied by an inverter alarm or a loss of power.
If there is an electrical alarm, repeated protective-device trip, unusual heat, smell or sound, keep clear of the equipment and contact a qualified installer promptly.
Information to collect before contacting support
A short, complete fault report is more useful than "the stick is flashing". Include:
- datalogger model and serial number;
- inverter model and serial number;
- PWR state, COM state and NET state;
- a ten-second video of any flash pattern;
- SolisCloud plant name and last update time;
- whether monitoring ever worked correctly;
- date and time the issue began;
- any router, network-name or password change;
- router make/model and whether 2.4 GHz is available;
- the exact message shown in SolisCloud;
- installer name and installation date, if known.
Frequently asked questions
Does a solid NET light mean my solar system is generating?
No. It confirms the logger's connection to the server. Check COM, the inverter's own visible status and current SolisCloud data separately.
What does a solid COM light mean?
Solis defines it as successful communication between the datalogger and inverter. It does not by itself confirm internet or server access.
Why can the app be offline when the inverter looks normal?
Monitoring has its own logger, home-network and server path. A network problem can interrupt fresh cloud data without proving an inverter fault.
Should I twist or unplug the logger if COM is not solid?
No. Solis warns that rotating the logger body can damage or loosen the COM port and says an installed logger should not be disconnected without permission from support.
Which datalogger does Solarboss currently list?
The Solarboss Solis S2-WL-ST Wi-Fi/LAN USB datalogger is model SOL-S2-WL-ST-USB and requires a compatible USB COM port.