Technical Support

When the signal is lost on an ENTTEC DMX device the last value is held until either the signal returns or the device is power cycled. 

If the device supports LTP merging, and there are two eDMX sources being received, if one source drops out, the remaining source will be transmitted. Once the 1st source reconnects, it will be the "latest" data so it will take precedence and control drive the fixture.

There are several different methods of merging & combining DMX. We’ve outlined the methods below alongside a list of the ENTTEC products these are supported by:

sACN Priority Merging (Network Level)

Each port (Universe/Source) can be set at a priority level between 1 and 200 (200 being the highest). If there are two or more sources of sACN on a network, both sending the identical universe number, the universe with the highest sACN priority will be used by the DMX node to output. If one of the sACN sources goes offline, the source with the next highest priority will be used.

The sources will merge on an HTP (highest-takes-precedence) basis if they both have the same priority.

The default sACN priority is 100.

All ENTTEC sACN products work on a per-universe priority – not per channel.

HTP (Highest Takes Precedence)*:

Each eDMX stream’s sources channels are compared to see which value is the highest; these will be merged and output.

For example:

If source A has channel one at 50% and source B has channel one at 75%, both transmitting the same universe, the DMX output from the node on channel one will be 75%.

Be aware that in this example, the 50% value on source A would still be active, meaning if source B’s value fades to 30%, the dimming will stop at 50%.

To give a single source complete control of the output, set all channel levels to 0 on all other sources.

LTP (Latest Takes Precedence)*:

LTP (Latest Takes Precedence) is a helpful way to control intelligent lighting parameters that don’t relate to intensity or additive colour mixing. Suppose you need a colour wheel to change from blue to red or a position to move from up to down. In that case, you want it to happen as you expect, no matter if the DMX value of that position or state is low or high, not be locked at a value from another source like you would see if you had a competing eDMX data stream when using an HTP merge.

LTP control channels send the latest change of instruction to an intelligent fixture parameter, and nothing changes until it sends another one on that channel.
LTP control channels are used in most non-dimmable fixture parameters and can be thought of as more of a dynamic switch of control source when a change is made instead of a merge of all values.

DATAGATE Mk2 (Discontinued May 2022):

ENTTEC Datagate Mk2 Priority Merge:

If source A stops, an internal timer begins; if the timer reaches the user-defined timeout, the output will switch to source B. When source A recovers, its output will switch back to source A.

The Timeout is defined in seconds, based on the wait time before switching to source B. Priority Merge can be used as a backup system.

ENTTEC Datagate Mk2 Switcher 1-2:

A trigger channel can switch the output of a source between Output A and Output B.

When the trigger channel is greater than the set value, the output will switch to Output B; if the trigger channel value is below, it will stay on Output A.

ENTTEC Datagate Mk2 Switcher 2-1:

A trigger channel can switch the output source between Input A and Input B. 

When the trigger channel is greater than the set value, the output will switch to Output B; if the trigger channel value is below, it will stay on Output A.

Merging is only available when the DMX port is set to Output. If the source is the same protocol and universe, two different eDMX (Art-Net/sACN) sources (from separate IP addresses) values can be merged. 

If the device receives more than two sources whilst a non-sACN priority merge is enabled, this could result in unexpected data affecting the lighting fixtures, potentially causing flicker. Several ENTTEC devices indicate this (please view the product-specific manuals for more information).

Whilst merging is enabled, if either one of the two sources stops being received, the failed source is held in the merge buffer for 4 seconds. If the failed source returns, the merge will continue; otherwise, it will be discarded, and the other source will take priority. To completely clear a merge of a removed value, a power cycle of the device may be needed. 

 **This can accept multiple sources

Flickering may occur if:

• Merging is disabled, and multiple sources are sent on the same eDMX universe.
• If more than two eDMX sources are detected (Only two sources are supported for merging)
• If both eDMX sources originate from the same IP address.