Dimetix D-Series Add-On Configuration

Configuration Parameters

In addition to the GW4 configuration parameters the add-on has the following specific parameters:

Dimetix Add-On Parameters

Key	Type	Default	Description
PowerOnDelay	Number	1000	Delay in milliseconds after activating the external power relay before RS-485 communication starts
TrackingStartDelay	Number	500	Delay in milliseconds after starting buffered tracking before values are read
samplingTimeMs	Number	100	Sampling interval supplied to the Dimetix buffered tracking command; 0 requests the maximum available measurement rate
avgSamples	Number	10	Number of valid distance measurements used to calculate the transmitted average
filterLength	Number	0	Length of the Dimetix measurement filter
filterSpikes	Number	0	Number of minimum/maximum pairs excluded by the Dimetix spike filter
filterErrors	Number	0	Dimetix filter error suppression setting

Power-On Delay

PowerOnDelay defines the time between enabling the Gateway V4 VOUT channel and starting communication with the Dimetix laser. The delay allows an external power supply or switching circuit enough time to power up the laser before RS-485 communication begins.

Example:

PowerOnDelay = 1000

This results in a delay of one second after the laser power supply is enabled.

Tracking Start Delay

TrackingStartDelay defines the time between starting buffered tracking and reading the first measurement from the tracking buffer. The delay is applied after the sNf command. This is different from PowerOnDelay, which is applied before communication with the sensor starts. A sufficiently long tracking start delay allows the internal Dimetix filter to fill and the measured value to settle before the Gateway V4 starts collecting samples.

Example:

TrackingStartDelay = 12000

This causes the Gateway V4 to wait 12 seconds after starting buffered tracking before reading measurements.

Buffered Tracking

Measurements are performed using the Dimetix buffered tracking mode. The firmware starts buffered tracking using:

sNf+<sampling-time>

For the currently supported sensor address 0, a command can for example be:

s0f+100

The configured value of samplingTimeMs is passed to the buffered tracking command.

A value of:

samplingTimeMs = 0

results in:

s0f+0

A sampling time of 0 requests measurements as fast as the Dimetix sensor can provide them. The actual measurement rate depends on the connected Dimetix sensor, measurement conditions and sensor configuration.

Reading Buffered Measurements

Buffered measurements are retrieved using:

sNq

For device address 0:

s0q

The response contains both the measured distance and a tracking buffer status. The firmware evaluates the buffer status before accepting a measurement. A measurement is only included in the averaging operation if a valid value is available.

Averaging

avgSamples defines how many valid measurements are collected before the result is calculated.

For example:

avgSamples = 10

causes the firmware to collect 10 valid measurements. The transmitted distance value is the arithmetic mean of these samples. Invalid measurements and unsuccessful communication attempts are not included in the average. If the required number of valid measurements cannot be collected, the measurement cycle results in an error instead of a distance value.

Filter Configuration

Before buffered tracking is started, the firmware configures the internal Dimetix measurement filter. The command has the following structure:

sNfi+<length>+<spikes>+<errors>

The values are taken from:

• filterLength
• filterSpikes
• filterErrors

For example:

filterLength = 32
filterSpikes = 2
filterErrors = 2

results in:

s0fi+32+2+2

This configures:

• Filter length: 32
• Spike suppression: 2
• Error suppression: 2

A longer filter can reduce measurement noise but also increases the time required until the filter contains enough measurements. TrackingStartDelay should therefore be selected according to the configured filter and the measurement conditions.

warning

The configured filter parameters must form a valid filter configuration supported by the connected Dimetix D-Series sensor.

Refer to the Dimetix D-Series documentation before changing these parameters.

Filter Length

filterLength defines the length of the internal Dimetix measurement filter.

Valid values are 2 to 32.

A value of 0 disables filter configuration by the Gateway V4. In this case, no sNfi command is sent and the existing filter configuration of the Dimetix sensor is left unchanged.

Example:

filterLength = 32

Filter Spike Suppression

filterSpikes defines the number of minimum/maximum value pairs that are excluded from the averaging operation within the Dimetix filter window.

For example:

filterSpikes = 2

excludes the two lowest and the two highest measurement values from the filter calculation.

Filter Error Suppression

filterErrors defines the maximum number of sensor errors within the filter window that can be suppressed without immediately producing an error at the sensor output.

Example:

filterErrors = 2

allows up to two sensor errors within the configured filter window to be suppressed.

Filter Parameter Validation

The filter parameters must satisfy the Dimetix filter constraint:

2 × filterSpikes + filterErrors <= 0.4 × filterLength

Invalid filter parameter combinations are rejected by the firmware.

Application-Specific Non-Default Values

For applications requiring stronger filtering, the following configuration can be used as a starting point:

Parameter	Value
PowerOnDelay	1000
TrackingStartDelay	12000
samplingTimeMs	0
avgSamples	10
filterLength	32
filterSpikes	2
filterErrors	2

With a filter length of 32, the longer TrackingStartDelay allows the internal sensor filter to fill and settle before the Gateway V4 starts collecting measurements. The values should be adjusted to the connected sensor, target surface and installation conditions.