Emerald K6/M3D logs

Overview

Full support for Emerald ECU log files from K6, M3D, and compatible ECU models. Emerald ECUs are popular in the British motorsport and classic car communities.

Supported File Format

• Type: Binary format (dual-file system)
• Extensions: .lg1 (data) + .lg2 (channel definitions)
• Source: Logged directly by Emerald ECU via EM Soft
• Note: Both files must be in the same directory

No Export Required

Emerald ECUs log directly to LG1/LG2 format. Simply load either the .lg1 or .lg2 file into UltraLog - both files are automatically loaded together.

How to Log with Emerald EM Soft

1. Connect to your Emerald ECU with EM Soft
2. Go to Logging section
3. Select channels to log
4. Click Start Logging
5. Drive/run the engine
6. Click Stop Logging
7. Save the log files (both .lg1 and .lg2 will be created)

Binary Format Details

Emerald uses a dual-file binary format:

• .lg1 file - Contains the actual time-series data values
• .lg2 file - Contains the channel ID for each of the 8 logger slots and the logger unit settings
• Data stored as binary values with timestamps
• Both files must be present in the same directory for UltraLog to load the log

Supported Channels

The .lg2 file stores a channel ID for each of the 8 logger slots. UltraLog maps these IDs to channels:

EM Soft label	UltraLog channel	Unit	Status
Engine Speed	RPM	RPM	Confirmed
Throttle Pos	TPS	%	Confirmed
AFR/Lambda	Lambda Sensor Voltage	V	Confirmed (see note)
MAP	MAP	kPa	Confirmed
Ign Adv	Ignition Advance	°	Confirmed (see note)
Inj Duration	Inj Duration	%	Confirmed
BoostPWM	Boost PWM	%	Confirmed
Load site	Load Site	0-15	Confirmed
AirTemp	Air Temp	°C	Not yet confirmed
CoolantTemp	Coolant Temp	°C	Not yet confirmed

Other channel IDs show as Channel N (ID x) with the raw value, or use a name that is not yet confirmed. If a channel shows the wrong name or value, open an issue and attach the .lg1/.lg2 pair and a screenshot of the same point in EM Soft.

Notes:

• Lambda Sensor Voltage is the K6's own lambda input in volts (0-1 V). If a wideband controller feeds that input, convert the voltage to AFR with a computed channel (see Computed Channels) that uses your controller's output curve.
• Ignition Advance uses an offset worked out from log data (5.5° at idle, 14-17° at full boost on a turbo engine). Compare it with EM Soft for your log before you use it for tuning.
• MAP is stored in the pressure unit the EM Soft logger was set to. UltraLog reads that setting from the .lg2 file and shows kPa. Only the kPa and bar settings are supported; with any other setting MAP values are wrong.
• If a log has two channels with the same name, the confirmed one keeps the plain name and the other gets its channel ID added, for example Ignition Advance (ID 21).

Important Notes

• Both files required: You must keep the .lg1 and .lg2 files together in the same directory
• Load either file: UltraLog can be pointed at either file - it will automatically find and load the companion file
• File naming: The files must have matching base names (e.g., mylog.lg1 and mylog.lg2)