About Presets

The DM84 stores its settings in a special nonvolatile memory area, one that preserves its data when the device is powered down. When the DM84 is powered up, a group of settings, called a preset, is copied from the nonvolatile memory and becomes what is called the active preset. It's the active preset that controls the operation of the DM84 when it starts running.

The nonvolatile memory in the DM84 holds a total of 24 presets, which are identified as "Preset 1" through "Preset 24". At any time, the active preset can be replaced by a another preset selected from the nonvolatile memory, this is called a preset recall. This allows the DM84 to be completely reconfigured "on the fly".

Certain DM84 settings can be protected from change when a preset recall is executed. This is done by using the Preset Recall Protected Settings feature in the control panel.

For additional flexibility, the choice of preset recalled at system powerup is selectable. This is called the powerup default preset.Two options are available:

A specific preset is assigned (by preset number)
The preset most recently used is remembered at the moment of system powerdown and becomes the preset recalled when the system is next powered up. This is called the last used default preset option, and is useful when continuity of system configuration is needed across power up/down cycles.

It is important to remember that the active preset is just a copy of the original preset stored in the nonvolatile memory. When changes are made to the DM84 settings using the control panel, it is only the active preset that is modified, the original preset is untouched. When the DM84 is powered down, the active preset is discarded.

However, the active preset can be written back, or stored into the nonvolatile memory to save changes that would otherwise be lost when the DM84 is powered down. The active preset can be stored to any of the 24 preset locations. Don't forget to do this when making changes to a preset that are intended to be permanent!

Presets can be given a brief description as documentation or to serve as a title. The preset description can be read by control system using the predesc command for display purposes.

Whenever the PC is connected to the DM84, the control panel reflects the settings held in the active preset and these can be saved to a preset file for future reference. This can be useful for documentation or troubleshooting purposes. The reverse is also true; if the PC is connected to the DM84, the control panel can be used to load a preset from a preset file, making that preset the active preset in the DM84.

Setting up the DM84

When a DM84 ships from the factory, all 24 presets are initialized to default settings, and the powerup default preset is preset number 1. Setting up the DM84 prior to installation involves replacing one or more of the 24 presets. Read on to see how this can be done.

The best technique is to use the control panel in offline mode to create a preset from scratch. Each tab in the control panel contains settings for a particular signal processing block, and the tabs are arranged left to right in the order of signal flow in the DM84. System setup typically begins with the Inputs tab and progresses rightward, following the signal flow. Once the preset has been created, it needs to be saved to disk as a preset file. Then it can be loaded later for transfer to a DM84, we'll discuss this process next.

When the PC is connected to a DM84, settings information can flow between the control panel and the DM84 in both directions. When the connection is first made, the active preset data flows from the DM84 to the control panel, so that the control panel is synchronized to the current state of the DM84. However, once connected, if a preset file is loaded from disk the data from the preset file flows to the DM84 and overwrites the active preset.

As mentioned before, the active preset can be stored into one of the 24 preset locations in the nonvolatile memory, thereby completing the process. So the flow is: preset file to active preset to nonvolatile device memory.

Here are the steps to follow:

Create a preset using the control panel in offline mode.
Give it a description.
Save the preset to a file.
Determine what preset location will be used to store it in the device memory.
Connect to the DM84 using the USB or serial port.
Load the preset file from disk. The settings from the file will be sent to the DM84, and overwrite the active preset.
Store the settings (now the active preset) to device memory at the assigned preset location.

Naturally a preset may need to be changed later on. Here are the steps to follow:

Connect to the DM84.
Recall the preset that needs to be modified.
Make the changes using the control panel.
Update the description if necessary.
Store the settings back to device memory, at the same preset location they were recalled from.
Save the preset to disk file for future reference.