DL-01 RS232-to-WiFi Gateway

Wireless telemetry bridge for Teltonika GPS/telematics trackers — User Manual

v1.5.4 FMC125 FMC650 MQTT Codec 8E WiFi 802.11 b/g/n

1. Overview

DURALINK is a compact WiFi gateway that sits between a Teltonika GPS/telematics tracker and your data infrastructure. It receives telemetry data from the tracker over a standard RS232 connection and forwards it to your MQTT broker or Teltonika-compatible server over WiFi.

Once installed, you may configure the device via its built-in Access Point. The device creates its own WiFi hotspot that you connect to with any browser for full configuration — no software installation, drivers, or laptop required in the field.

DURALINK stores records locally on an SD card when the server connection is unavailable, then automatically delivers them when connectivity is restored — ensuring no data is lost in areas with intermittent WiFi or server outages.

2. Key Features

Zero-Cable Configuration	All settings configured wirelessly via web browser. No USB cable needed after initial installation.
Mobile-Friendly Portal	Built-in web portal works on any phone or tablet browser without installing an app.
Dual Tracker Support	Compatible with Teltonika FMC125 and FMC650 GPS trackers out of the box.
Auto-IMEI Detection	Device automatically reads the tracker's IMEI number — no manual entry required.
MQTT & Codec 8E Output	Choose between JSON over MQTT or Teltonika Codec 8 Extended binary TCP to match your platform (compatible with Flespi, Wialon, and others).
Multi-Network WiFi Roaming	Store up to 5 WiFi networks. DURALINK connects to the strongest available signal automatically.
Store-and-Forward	Records saved to SD card while offline and delivered automatically when the connection returns. No data is lost.
Hardware Real-Time Clock	Accurate timestamps on every record, even without GPS lock or internet access.
Automatic NTP Sync	Synchronises time with internet NTP servers whenever WiFi is connected.
Browser OTA Firmware Update	Upload new firmware directly from the portal. No USB cable or site visit required.
Remote Reboot	Restart the device remotely from the portal without a physical site visit.
Factory Reset via BOOT Button	Hold the BOOT button for 5 seconds to restore all settings to factory defaults.
Unique Device Identity	Each unit broadcasts a unique hotspot name (DuraLink-XXXX) based on its hardware ID for easy identification in multi-unit deployments.
Settings Preserved on Update	WiFi credentials, server settings, and all configuration are retained when firmware is updated.

3. What You Need

Included

DURALINK device (firmware pre-installed)

Required — provided by installer

Item	Notes
Teltonika GPS tracker	FMC125 or FMC650 with an RS232 port
RS232 cable	Between the tracker's RS232 port and DURALINK
MicroSD card	Any capacity; must be FAT32 formatted — used for store-and-forward buffering
WiFi network	With internet access for data delivery and NTP time sync
Power supply	9V - 26V

Physical installation and wiring must be performed by a qualified technician following the hardware installation guide provided separately.

4. First-Time Setup

4.1 Wiring Diagram

4.2 Configuration Steps

1. Power on the device

Apply 9V - 26V power. DURALINK starts up and broadcasts its own WiFi hotspot within 10 seconds.

2. Connect to the DURALINK hotspot

On your phone or laptop, open WiFi settings and connect to:

Network Name (SSID)	`DuraLink-XXXX` (last 4 characters are unique to your device)
Password	`rs232config`

3. Open the configuration portal

Open any web browser and navigate to http://192.168.4.1. The DURALINK portal opens automatically.

4. Connect to your WiFi network

Go to the WiFi tab, click the scan button, select your network, enter the password, then click Save & Reconnect.

5. Select your tracker type

Go to the Device tab, select FMC125 or FMC650, click Save & Reconnect, then power-cycle the device.

6. Configure your server

Go to the Server tab, choose MQTT or Codec 8E TCP, enter your server address and credentials, then click Save & Reconnect.

7. Verify operation

Check the status bar at the top of the portal. All indicators should show green. The device is now operational.

The portal is always accessible at http://192.168.4.1 even after the device connects to your router. You can reconfigure at any time without interrupting data transmission.

5. Configuration Portal

The DURALINK portal is a web interface accessible at http://192.168.4.1 from any device connected to the DURALINK hotspot or the same local network. No app or software installation is required.

5.1 Status Bar

The top of the portal shows live status indicators for all subsystems:

Indicator	Meaning
WiFi: NetworkName (IP)	Connected to your router. The assigned IP address is shown.
WiFi: Offline	Not connected. Check credentials in the WiFi tab.
MQTT/TCP: Connected	Server connection active. Data is being delivered.
MQTT/TCP: Offline	Server unreachable. Records are being stored on the SD card.
SD: Mounted	SD card detected and working correctly.
SD: Not mounted	SD card missing or unreadable. Records cannot be buffered locally.
Device: FMC125 / FMC650	Currently active tracker input mode.

Below the indicators, a storage bar shows SD card usage (used / total MB) and the number of records currently waiting to be delivered to the server.

5.2 WiFi Tab

Configure which WiFi networks the device connects to. Up to 5 networks can be stored — DURALINK automatically connects to the strongest known network at startup.

Setting	Description
Network Scan	Click the scan button to discover nearby WiFi networks. Click any result to auto-fill the network name.
Network SSID	The name of your WiFi network.
Password	Your WiFi password. Hidden by default — use the show/hide toggle to reveal.
Add / Remove	Manage up to 5 network profiles. Device picks the strongest available at startup.
CSV Import	Upload a `.csv` file to add multiple WiFi profiles at once.
CSV Export	Download your current WiFi profiles as a backup file.

Click Save & Reconnect to apply changes.

5.3 Device Tab

Select which Teltonika tracker is connected to the RS232 port.

Option	Use When
FMC125	A Teltonika FMC125 tracker is connected via RS232.
FMC650	A Teltonika FMC650 tracker is connected. The FMC650 must be set to Rec to LCD output mode in the Teltonika Configurator application.

After changing the device mode, click Save & Reconnect then power-cycle the device (remove and restore power) for the change to take effect.

5.4 Server Tab

Choose where DURALINK sends telemetry data and configure the transport settings.

Setting	Description
Output Mode	MQTT (JSON) — sends JSON records to an MQTT broker. Codec 8E TCP — sends Teltonika binary packets to a compatible server.
Broker / Server Host	IP address or hostname of your MQTT broker or Codec 8E server.
Port	TCP port number. MQTT default: `1883`. Codec 8E: as configured by your platform.
MQTT Topic	The topic records are published to (MQTT mode only).
QoS	MQTT Quality of Service: `0` = fire and forget, `1` = at least once, `2` = exactly once.
Keep-Alive	MQTT keep-alive interval in seconds.
Device IMEI	Auto-filled when the tracker IMEI is detected. Required for Codec 8E mode.

Click Save & Reconnect to apply changes.

5.5 Maintenance Tab

System tools and device management functions.

Access Point Settings

Change the name (SSID) and password of the DURALINK's own WiFi hotspot.

If you change the AP password and forget it, you will need to perform a factory reset using the BOOT button to restore access.

SD Storage

Displays live SD card usage (used / total MB) and the number of records currently waiting to be delivered to the server.

Reboot Device

Remotely restarts DURALINK. Useful after configuration changes that require a restart without a physical site visit.

Delete All Records

Permanently deletes all records stored on the SD card and internal storage. This action cannot be undone.

Only delete records after confirming they have been delivered to your server, or if you intentionally want to discard all buffered data.

Firmware Update (OTA)

Upload new firmware directly from your browser. See Section 8 — OTA Firmware Update for the complete procedure.

Device Info

Displays the device MAC address (unique hardware identifier) and the currently installed firmware version. Useful when managing multiple deployed units.

6. Data Output Reference

6.1 MQTT — JSON Format

In MQTT mode, each tracker record is published as a JSON object to the configured topic:

{
  "Timestamp": "1747187905000",
  "Priority":  "0",
  "Latitude":  "13.756331",
  "Longitude": "100.501762",
  "Altitude":  "12",
  "Angle":     "270",
  "Speed":     "0",
  "HDOP":      "0.7",
  "Sat":       "8",
  "IO_Data": {
    "22":  "4",
    "66":  "12133",
    "67":  "0",
    "71":  "1",
    "181": "0",
    "239": "0"
  }
}

Field	Description
`Timestamp`	Unix time in milliseconds, sourced from the hardware RTC — accurate even without GPS lock or internet access.
`Priority`	Record priority from the tracker: `0` = Low, `1` = High, `2` = Panic.
`Latitude` / `Longitude`	GPS coordinates in decimal degrees.
`Altitude`	Altitude above sea level in metres.
`Angle`	Vehicle heading in degrees (0–359, where 0° = North).
`Speed`	Speed in km/h.
`HDOP`	GPS horizontal dilution of precision — a lower value indicates better positional accuracy.
`Sat`	Number of GPS satellites currently locked.
`IO_Data`	Key/value map of Teltonika IO element IDs and their values. Refer to the Teltonika IO element documentation for ID definitions specific to your tracker model.

6.2 Codec 8 Extended — Binary TCP

In Codec 8E mode, DURALINK sends standard Teltonika Codec 8 Extended binary packets over TCP. This mode is compatible with major fleet management platforms including:

Flespi (app.flespi.io)
Wialon (wialon.com)
Any Codec 8 Extended compliant TCP server

No additional configuration is required on the DURALINK side beyond entering the server address, port, and verifying the IMEI is correct in the Server tab.

7. Store-and-Forward

DURALINK is designed to never lose a telemetry record, even when the WiFi or server connection is temporarily unavailable.

Tracker sends a record via RS232

↓

Record saved to SD card immediately
Publisher task checks server connection every 5 seconds

↓

Connected

Send record to server → delete from SD card

Offline

Leave record on SD card → retry next cycle

Behaviour	Detail
Record naming	Files stored sequentially: `00000001.jsn`, `00000002.jsn`, and so on.
After reboot	Numbering resumes from the highest existing file — no records are skipped or duplicated.
During outage	Records accumulate safely on the SD card with no data loss.
On reconnect	All pending records are delivered to the server in sequence, automatically.
No SD card	DURALINK falls back to direct publish. If the connection fails at the time of transmission, that record is not retained.

The storage bar in the portal shows the current pending record count. A growing count indicates the server has been offline — records will deliver automatically once the connection is restored.

8. OTA Firmware Update

DURALINK supports wireless firmware updates directly from the web portal. No USB cable or site visit is required.

Obtain the firmware update file (.bin format) from Maruko Dura Solusi before proceeding. Ensure your device is connected to the DURALINK hotspot or the same local WiFi network as the device.

1. Open the portal

Connect to the DURALINK hotspot and navigate to http://192.168.4.1.

2. Go to Maintenance tab

Click the Maintenance tab in the portal navigation bar.

3. Select the firmware file

Under Firmware Update, click Choose .bin file and select the firmware file provided by your supplier.

4. Start the upload

Click Upload & Install. A progress bar shows the real-time upload status. This takes approximately 10–30 seconds depending on file size.

5. Wait for reboot

When the upload completes, the device automatically reboots into the new firmware. Allow approximately 10 seconds.

6. Verify the update

Reconnect to the portal, go to the Maintenance tab, and confirm the version number shown in Device Info.

Do not remove power from the device while the upload progress bar is active. Interrupting a firmware update may leave the device in an unbootable state requiring service.

All WiFi credentials, server configuration, and device settings are preserved across firmware updates. Only the firmware code is replaced.

9. Factory Reset

If you have forgotten the AP hotspot password or need to fully restore DURALINK to its default configuration, a factory reset can be performed using the physical BOOT button on the device.

1. Locate the BOOT button

Find the button labelled BOOT on the DURALINK device.

2. Hold the button for 5 seconds

While the device is powered on, press and hold the BOOT button continuously for 5 seconds.

3. Wait for automatic reboot

The device erases all saved configuration and restarts automatically. This takes approximately 5 seconds.

4. Reconnect using default credentials

After reboot, reconnect using the factory default hotspot name and password shown in the table below.

A factory reset permanently clears all saved WiFi networks, server configuration, MQTT settings, and any custom AP name or password. The device must be fully reconfigured after a reset.

Default Settings After Reset

Parameter	Default Value
AP Network Name (SSID)	`DuraLink-XXXX` — last 4 characters of device MAC address
AP Password	`rs232config`
Portal URL	`http://192.168.4.1`
WiFi profiles	None — cleared
Server / MQTT settings	None — cleared

10. Troubleshooting

Symptom	Likely Cause	Resolution
No data appearing on server	Wrong device mode or tracker not configured correctly	Verify the Device tab setting matches the connected tracker model. For FMC650, confirm the tracker is set to Rec to LCD output in the Teltonika Configurator.
Status bar: MQTT/TCP Offline	Server unreachable or incorrect credentials	Double-check server address, port, and credentials in the Server tab.
Status bar: WiFi Offline	Wrong WiFi password or router out of range	Re-enter WiFi credentials in the WiFi tab. Confirm the router is reachable and broadcasting.
Status bar: SD Not Mounted	SD card missing or incorrectly formatted	Reinsert the SD card and ensure it is formatted as FAT32.
Records accumulating, not sending	Server connection is offline	Check Server tab settings. Records will deliver automatically once the connection is restored — no manual action required.
Timestamps are incorrect	NTP sync failed or RTC battery depleted	Confirm the device has internet access via WiFi. If timestamps remain wrong, the RTC battery may need replacement — contact your supplier.
FMC650: no records appear	FMC650 not set to Rec to LCD mode	In the Teltonika Configurator, set the FMC650 RS232 data output mode to Rec to LCD.
Cannot connect to portal	Not connected to the DURALINK hotspot	Disconnect from any other WiFi network and connect to `DuraLink-XXXX` first, then navigate to `http://192.168.4.1`.
OTA update fails or shows error	Weak WiFi signal or incorrect firmware file	Stay close to the DURALINK hotspot during upload. Confirm the `.bin` file was obtained from Maruko Dura Solusi.
Device unresponsive after config change	Restart required	Use Reboot Device in the Maintenance tab, or power-cycle the device.
Forgot the AP hotspot password	Password changed in Maintenance tab	Perform a factory reset: hold the BOOT button for 5 seconds. All settings will return to factory defaults.

11. Product Specifications

Model	DL-01 RS232-to-WiFi Gateway
Firmware Version	v1.5.4
Supported Trackers	Teltonika FMC125, Teltonika FMC650
Output Protocols	MQTT (JSON), Teltonika Codec 8 Extended (TCP)
Wireless Standard	WiFi 802.11 b/g/n, 2.4 GHz
WiFi Profiles	Up to 5 (auto-selects strongest signal)
RS232 Baud Rate	115200 bps
Local Storage	MicroSD card — FAT32, any capacity
Real-Time Clock	DS3231M hardware RTC, battery-backed
Time Synchronisation	Automatic NTP sync on WiFi connection
Configuration Interface	Web browser — no app or software required
Configuration URL	http://192.168.4.1
Default AP Network Name	DuraLink-XXXX (last 4 characters of device MAC address)
Default AP Password	rs232config
Factory Reset	BOOT button — hold 5 seconds
Firmware Updates	Over-the-air (OTA) via browser — no USB cable required
Settings Persistence	Retained across power cycles and firmware updates
Power Input	9V - 26V

12. Changelog

Version	Summary
v1.5.4	Added circular buffer (oldest records automatically deleted when 254-record limit is reached) to ensure continuous operation.
v1.5.3	Added internal memory (1 MB) fallback for storing records when SD card is absent; minor bug fixes and improved diagnostics.
v1.5.2	Revised manual design; BOOT button factory reset feature added
v1.5.1	Browser-based OTA firmware update (stable dual-slot); improved portal stability
v1.5.0	Browser OTA introduced; unique device AP SSID; password show/hide toggle; MAC address display in portal
v1.3.1	DURALINK branding; Maintenance tab with remote reboot and SD card wipe
v1.3.0	FMC650 Rec-to-LCD tracker support added
v1.2.0	Multi-network WiFi roaming (up to 5 profiles); WiFi CSV import/export
v1.1.0	Codec 8E TCP output mode; DS3231M hardware RTC support; SD card store-and-forward