Adjustable parameters

The following parameters can be set:

Number of pixels

The connected number of pixels must be specified per channel in the CoE object 0x80p0:11 Number of Pixel. An error message will be output if pixels outside of this range are written by the process data.

A total of 2048 pixels can be written by the EL2574.

The maximum number of pixels per channel is determined by the number of configured channels.

Chip type

The LED chip type used must be specified per channel in the CoE object 0x80p0:12 Chip Type. Only then the high, low and reset timings specified by the chip type are observed.

Depending on whether a channel is configured for a synchronous chip type (with clock) or an asynchronous type, different chip types are available for selection in the drop-down list.

Color format

The LEDs differ in their number of colors (RGB or RGBW) and in the sequence or format of the interconnected colors.

Here the connected color format must be specified in the CoE object 0x80p0:13 Color Format so that the respective color value is also correctly displayed in the process data.

Gamma correction

The gamma value can be used to adjust the scaling of the output. The brightness behavior can, for example, be approximated to the perception of the human eye.

Gamma can be set per channel in the CoE object 0x80p0:1E Gamma Correction. If this value is set to 1.0, the scaling is linear.

The output is calculated using the following relationship: (Current_process_data_value/Maximum_process_data_value)^Gamma

The adjustable value is between 0.2 and 5. The specified gamma value is applied to all colors.

Example application for the linearization of brightness for the human eye:
The brightness perceived by humans increases more steeply in dark areas and less steeply in bright areas. The human eye is assigned a gamma value of approx. 0.3 to 0.5. If you want to perceive the brightness signal of a display device (e.g. a monitor or an illumination device) linearly, you have to pre-distort it with the reciprocal of the gamma value (approx. 1/0.3 = 3.3 to 1/0.5 = 2) so that the two non-linearities cancel each other out and the course appears linear to the observer.
For the gamma values, a value between 2 and 3.3 would thus have to be specified for the human eye.

Total brightness

The total brightness of a channel can be specified via the CoE object 0x80p0:1F Brightness Scale .

This value is set to 1.0 by default, which corresponds to 100 % brightness. The brightness can be set between 0 and 100%.

Behavior in watchdog case

Normally, the last status is maintained in the watchdog case, since no new data is sent from the terminal. However, it is also possible to display a specified color on all connected LEDs on a channel in the event of a bus communication failure.

This can be used, for example, for error indication, so that in the watchdog case the LEDs light up red, for example, to signal the error. In the watchdog case, the values entered in the CoE for gamma and total brightness are retained.

Cyclic frame output

The cyclic frame output is enabled by default in the CoE object 0x80p0:02 Enable Cyclic Frame Output .

The data from the frame buffer is sent to the strip every 250 ms. As a result, possible false images caused by interference and influences on the cable are visible for a maximum of 250 ms. This cyclic sending can also be switched off if the application requires it.

Custom Settings

Custom settings can be made for the data rate, duty cycle, reset time and level.

These must be enabled via the CoE object 0x80p0:01 Enable Custom Settings.

Current specification

Some chip types require the specification of a current (e.g. TM1814).

This can be specified via the CoE objects 0x80p0:20 - 0x80p0:23 Set Driver Current. If this information is not required by the chip type it is ignored.