Here you can adjust the number of program buses used. It can be configured between 0 and 47. Program buses are always fed after the fader; with their help you can create channel groups and implement solo functions.

Here you can adjust the number of AUX buses used. It can be configured between 0 and 47.

AUX buses can be used “Pre” or “After” the fader, the AUX Gain per channel can also be adjusted. This is not adjusted in the Toolbox4 software, though, but at the Console of the RM4200D.

It is possible to talk into the summing bus using up to two signal paths. You can select these two signals at Talk 1 Source and Talk 2 Source. Any signal available on the TDM bus can be used as signal source for the Talk function. Mostly it is a microphone signal using a Fixed Processing (with compressor and limiter). Both Talk Sources are summed with the signal of the summing bus. The latter can be attenuated or switched off using the parameter Talk Attenuation between 0dB and Off (mute) in steps of 1dB.

To select the Talk signal source, first mark the desired bus in the list and then click the corresponding button Select. The Audio Sources Window opens and is active and you can select the desired audio source. You assign the source with the button Assign, alternatively you can double click the source or use Drag&Drop.

	Note
	The signals for Talk Source 1 and Talk Source 2 are identical for all summing buses, also the attenuation setting Talk Attenuation.

For each configured bus, you can assign two logic sources Talk 1 Condition and Talk 2 Condition , which activate the Talk function. By default, the Talk Condition is None for all buses. If this is not changed, talk into a summing bus is not possible.

To select the logic sources, first mark the desired bus in the list and then click the corresponding button Select. The Logic Sources Window opens and is active and you can select the desired logic source. You assign a source with the button Assign, alternatively you can also double click on the source or use Drag&Drop.

	Note
	If this talk function is not flexible enough for your application, you can program more complex talk functions using Output Functions. (see also Output Functions)

You can use any logic source available in the system as Talk Condition, as illustrated in the following examples:

	Note
	The key function Clean Feed Cut configurable in a Fader Module works before (pre) the Talk function. This means that talking is also possible with Clean Feed signal switched off.

In this input field, you can enter a new name for the bus selected in the list or change it. Instead of the pre-defined name, this label is displayed in the Audio Sources Window under Mixing/Busname L,R. In addition, the name of the bus in the first column of the list changes, too.

The function Output Select offers a flexible opportunity to supply the return circuit of a bus with another signal than the Clean Feed. This way, an alternative signal instead of the Clean Feed can be feed in. This feed happens before the functions Clean Feed Cut and Talk.

You can determine from which signal list the alternative signal for a certain Clean Feed bus should come.To achieve that, first mark the desired bus in the list, then select the desired signal list from the drop down menu Output Selector Source List.

In total, there are up to 10 different Source Lists in which you can select up to 150 sources. These 10 lists are also used for the Rotary Monitor Selectors. You can change the assignment of the signals to the lists under Audio System/Selector Source Lists. (see Selector Source Lists)

In order to use an alternative signal, the following steps are necessary:

	Tip
	If the assigned signal list contains only a single signal, the configuration of the 2nd step can be dropped. Then, you can start immediately switching between the Clean Feed and the alternative signal in step 1.

Examples:

• With this function, you can switch between an original and its associated Clean Feed signal. To achieve that, you have to define the source Mixing/Program Bus 1 in the assigned signal list as the alternative signal. This is the „original signal“!

• You can use a reference tone signal. To achieve that, you have to define a Fixed Processing with a Sine generator and enter it in to the assigned signal list. (see also Fixed Processing – Defining Fixed DSP Functions)

• You can output the Clean Feed of another Fader Channel. To achieve this, you have to enter this particular channel into the assigned signal list. Of course you can enter the Clean Feed signals of all Fader Channels into the list and let the user pick the desired one.

• If you assign a Clean Feed to a recording device like DAT, Tape or MD, you can carry out an output routing using the corresponding signal list. That way, you could for instance record a source directly while using the RM4200D for a different production task.However, a summing bus is consumed. Alternatively, for this application, the Rotary Monitor Selectors, the PC Routing Software or the routing functions of the keyboard are available.

	Note
	The selection of sources from an Output Selector Source List is always carried out with the Main Rotary Control of the Control Module selected with the ACCESS key or with the encoder assigned to the fader strip. Console keys can not be used to select sources.

A simple limiter can be used in each summing bus that does not consume any additional DSP resources. For this function, check the checkbox Limiter.

The Threshold of a limiter can be adjusted in a range between -30 dBint and +20 dBint, the decay time Release between 3 dB/s and 2 dB/s. The attack time can not be adjusted and is always “fast”.

The pre-defined setting of the Threshold is +9 dBint, since this level corresponds to 0 dBFS or maximum level for digital outputs with 9 dB headroom. Internal over modulation is limited this way.

	Note
	This limiter is part of the summing bus system and can not be adjusted using the DSP Control Software RM420-551 Access. The limiter is not a Fixed processing!

If further limiters are needed (e.g. a transient limiter), you can insert it as separate Fixed Processings after the sums. In this case, you should switch off the simple limiter here. (see also Fixed Processing – Defining Fixed DSP Functions)

In general, all summing buses are computed stereo for internal use, but they also can be used mono by mono summation (-3 dB) of the left and right channels. Switch off the checkbox Stereo to activate the mono summation. After that, the bus is displayed in the Audio Sources Windowunder the node Mixing as entry labelled Mono <Busname> only.

	Note
	Clean Feeds are internally created as stereo signals, too. It does not matter whether the source of the Fader Channel of the Clean Feed is mono or stereo.

If in a configuration a bus is to be used mono and stereo at the same time, the mono signal must be created using an Output Function.