The RM2200D consists of two main parts: the DSP Frame and the Mixing Desk. Both are coupled with a CAN bus cable. The DSP frame is a 3U rack unit, it contains the power supply and all the hardware necessary for the actual audio processing. In contrast, the mixing desk only acts as “remote control” for the DSP frame - there is no audio transmitted on the CAN bus, only control and status information.
Additionally, you can connect a PC to the DSP frame using either a serial connection or the TCP/IP protocol over Ethernet. This PC runs the RM2200D software, a standard Windows application. You use this software both to configure the RM2200D and to display its state during normal operation. (see also Operating the RM2200D )
The following picture shows the general structure of a RM2200D system. The DSP frame contains both the Audio and the Control Engine, all Control Modules are contained in the mixing desk.
The Audio Engine of the RM2200D runs on a high-performance DSP system (SHARC from Analog Devices). This DSP is connected to all audio inputs and outputs of the RM2200D. All audio processing is done here; the hardware provides enough performance to handle all audio signals simultaneously.
The Audio Engine receives its commands from the Control Engine, whenever a fader is moved or a key is pressed on the mixing desk. Depending on the actual configuration, the Audio Engine changes the way it processes the audio signals.
The Control Engine handles all communication between the control modules in the mixing desk, the Audio Engine and external devices. Most of the time it reacts to events coming from the mixing desk. For example, if you move a fader on the mixing desk, this event is transmitted on the CAN bus into the Control Engine. In turn, the Control Engine changes the level of the audio signal which is currently assigned to the fader just moved. The other way round, the Control Engine sends level information to the level meters in the mixing desk and controls the different LEDs and the LC display in the Master Control Module of the mixing desk.
If you run the RM2200D software on a PC connected to the DSP frame, the Control Engine also communicates to this software. Is transmits the level and status information to the PC and reacts to configuration changes made in the software.
The Control Engine communicates to external systems using General Purpose Inputs (GPI) and General Purpose Outputs (GPO). GPIs and GPOs are used to interface external devices to the RM2200D. They are electrical contacts which are available on the RJ 45 sockets on certain modules. However, the technical specifications both for inputs and outputs differ from module to module. (see Technical Specifications)
![[Warning]](../pics/warning.gif) | Warning |
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Before connecting any external devices to the GPIOs of the RM2200D, make sure you have read and understood the technical specifications of the GPIO connectors! Do not connect any equipment which can not operate within these specifications, otherwise you can damage both to the RM2200D and the external devices! | |
Examples for the use of GPIs and GPOs are:
Fader start contacts of CD players, DAT decks or tape machines to the RM2200D.
Light signalisation for On-Air, incoming telephone calls or other external events.
Integration of external talkback systems.
Connection of telephone hybrids or screener systems to the RM2200D.
The RM2200D is a flexible system that can be adapted to many applications. There are several combinations of modules in the DSP frame possible as well as different requirements for the use of the RM2200D. Thus, the Control System needs to adapt to different situations. This is done by using a special set of data which contains the actual “structure” of the current setup. This data is called Configuration Dataset or just Config for short. It is stored within the DSP and Communications Module of the DSP frame and controls the way the RM2200D works. The Config is stored, even if the power supply of the DSP frame is cut. Only if you upload a new Config, the old one is replaced.
You create and change the Config within the RM2200D software, using its Configuration Mode. To activate a new Config, you need to upload it to the RM2200D DSP frame. After the transfer is finished, the new Config becomes active. (see also About Configuration Data)
Every RM2200D is shipped from DHD with a standard Config preloaded. This Config is also on the CD shipped with the RM2200D. You can use it as a starting point for your own changes.
The RM2200D contains an Input Pool for the audio inputs. This feature allows you to put several input signals together in a group. You can than use a Pool Fader to assign any of the signals from this pool to a particular fader. However, if one input from the pool is already assigned to a fader, you can not assign it to another fader. If you want to put an audio input into the Input Pool, you have to use the RM2200D software. Check the option for the desired input in the section Frame I/O of the configuration dialog. (see also Frame I/O - Configuring the DSP Frame)
On the contrary, Fixed Faders are faders which have a permanently assigned input source that you can not change. This is for example useful for microphone channels that you want to assign to certain faders.
The RM2200D Selector works similar to the Input Pool. If you put an audio input into the Selector pool, you can choose it both for monitoring and as an alternative signal for clean feed output. (see also Frame I/O - Configuring the DSP Frame)
A Clean Feed is used to generate a special audio signal. This signal is usually the output of the mixer, but without the signal the clean feed is assigned to. Clean feeds are mostly used when connecting telephone hybrids or other external lines to the RM2200D.
You can define up to four clean feed signals in the RM2200D software. They are permanently assigned to the selected input signals. However, you can also choose to send signals from the Selector pool as back signals, if necessary. You just have to check the option Selector in the section Various of the configuration dialog. (see also Various - Configuring Level Meters and Clean Feeds)
When you are configuring the RM2200D, you need to know two important concepts which are used throughout this manual - Audio Sources and Logic Sources:
An Audio Source is any audio signal available within the RM2200D. These signals include:
Input signals coming from devices connected to the RM2200D.
Pre fader signals, program busses, Aux busses.
Cue bus, monitor bus, monitor selector inputs and clean feeds.
If you are using the RM2200D software for configuration, you will often need to assign audio sources in certain parts of the software. You will find all available audio sources in the Audio Sources window. (see also Audio Sources)
A Logic Source is a condition within the RM2200D which can be either active (“true”) or inactive (“false”). Depending on the configuration, logic sources are used to:
Switch GPOs on or off, i.e. to remote control external devices.
Switch LEDs on the mixing desk on or off.
Input external logic signals via GPI contacts.
Dim or mute monitor signals.
Insert talkback signals into the program bus or other audio signals.
Logic sources include the following conditions:
Fader start contacts.
GPI inputs.
Cue status for input signals. This condition becomes active if an input signal is assigned to a fader channel and this channel is in cue mode.
All keys on the Master Control Module. If any one is pressed, its associated logic source becomes active.
System events like On-Air logic 1 and On-Air logic 2, Alarm, Cue active and a few others. (On-Air logic 1 and 2 are for instance used to mute loudspeakers when microphone channels are opened.)
You only need to deal with logic sources when using the RM2200D software in Configuration Mode. When you need to select a logic source, the Logic Sources window will open and provide all available logic sources. The different logic sources are explained in more detail later in this manual. (see also Logic Sources)