Starting with the latest firmware versions of the HP100, the Helvest decoders include several new, important functional settings designed for more advanced applications or for model railway enthusiasts who are particularly demanding and attentive to every aspect. Both functions are integrated into CV252, and in this article, we will describe them in detail.
The “Multi Action” Function
When an accessory is activated, for example, when a switch is moved from position A to position B, it usually does not accept further commands until the movement is completed. This means that if a command is received to perform another movement (e.g., returning to A) before it reaches position B, this command is ignored by default.
This limitation was introduced to prevent errors caused by the way certain control centers or software solutions communicate (as we will explain later). At the same time, it reflects reality: a switch will not return to its starting position before completing its movement.
However, for some model railway enthusiasts, this can be problematic, particularly in cases of user error. For example, if a switch is moved from A to B, but this command was a mistake and the switch should immediately return to A, the reset command will be rejected in the default configuration.
By activating the “Multi Action” function, however, all commands are accepted, even those that contradict the last activated one. For instance, if the switch is moved from A to B and then immediately back to A, even though the movement to B has not been completed, the switch will execute all commands sequentially – even if they are repeated or issued multiple times.
How to Activate the “Multi Action” Function
In the DCC protocol, the “Multi Action” function is activated via CV252:
- Value 0 = deactivated
- Value 1 = activated
In MVnet, the option to activate this function will be available in the next version of LocHaus.
When Should the “Multi Action” Function Not Be Activated?
There are combinations of control centers and software that may cause commands to be repeated (e.g., if the network sends the same movement command to the switch dozens of times).
In such cases, activating the “Multi Action” function can overload the network and lead to unpredictable movements of the switch.
Based on our current knowledge, this issue occurs with control centers such as Digikeijs and Yamorc when combined with certain software (e.g., RocRail). With MVnet, however, communication is controlled directly by the computer, which avoids such problems.
From Which Firmware Version Is the Function Available?
The “Multi Action” function is available for the HP100 starting from firmware version 4.1. To check your firmware version, please refer to the label on the back of the circuit board.
The “No Repeat” Function
The “No Repeat” function can prevent repeated commands when the “Multi Action” function is activated. For instance, if the switch is in position “A” and is being moved to “B,” and then the “B” output is activated again – either due to user error or because the computer or control center repeats the commands – this function will ignore all further repeated commands. In other words, if the decoder receives, for example, ten identical “B” commands, only the first one will be processed.
How Is the “No Repeat” Function Activated?
If the value 3 is written to CV252, the “Multi Action” function remains active, and the “No Repeat” option is additionally activated.
From Which Firmware Version Is the Function Available?
The “No Repeat” function is available for the HP100 starting from firmware version 4.3. To check your firmware version, please refer to the label on the back of the HP100 circuit board.
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