Automated lighting consoles are full of features, many of which rarely get used. However there is one feature that is required for every single show: patching. A patch is a set of instructions that assign specific controls on the desk to fixtures and their attributes in the real world. Without a patch, no communication between the console and devices can take place. It is vital for lighting programmers to understand how to patch their console and how to use the various options within the patch window. While some of the terminology may change from desk to desk, the basic procedures remain the same regardless of the console.
The Basics
In the old days, patching was done with actual “patch cables” connecting lighting controls to specific dimmers or circuits. Now all patching is accomplished via computer systems and intuitive GUIs. Although the computers provide much ease in patching, they still serve the same basic purpose: connect controls to devices. With any modern lighting console, you must patch lighting fixtures before you can gain control of them. The process is rather similar and straightforward, regardless of the type of console.
First, you must select a fixture type from a library of fixtures. This will contain a mapping of the specific channels used and their purpose at different values. Next, you assign a console number to this fixture(s). Finally, you select an output line (universe) and starting channel. Most modern consoles utilize some format of DMX 512 (DMX, Art-Net, (s)ACN), but it is possible that you might have to also select a communication protocol to be used with a specific device.
As you match the unique console numbers with specific DMX universes and start addresses, you will be building and assigning the patch data. If the devices are not on the correct DMX universe, or they are set to different DMX start addresses from the patch, then you will not be able to properly control the devices. For this reason, it is very important for the patch information to match the settings in the actual lighting rig.
The Chicken and the Egg
When preparing for a production, a big question often arises as to who will create the patch information. The LD has made a plot, but may or may not have assigned console numbering and DMX information for the fixtures. Often the master electrician or the crew chief will determine the best patch, depending upon how they plan to cable the rig. In other cases, the programmer may patch the rig as he/she sees fit and then share the information with the crew.
Sometimes one person fills all these positions and simply plans the entire rig and patch himself. No matter who creates the patch, the lighting programmer must receive the data and enter it into the console accordingly. It is also important that the designer, programmer and ME/crew chief know the console fixture numbers, as this is how the units will be referred to throughout programming and show.
Multi-Part Fixtures
Many lighting products now contain multiple elements that have the same functionality, yet are contained within a single fixture. For instance, a moving head LED wash light might have three distinct rings of RGBW control as well as the standard, pan, tilt, intensity, strobe and other parameters. Typically this type of light will be controlled as four unique fixtures within the patch, thus giving unique control the to the individual elements. So one of these wash lights might be patched as console numbers 100-103 where 100 is the main unit (pan, tilt, intensity, strobe) and 101-103 are each of the RGBW rings. Two different fixture types would be used in the patching, with four total instances equaling one real world light. The reason for this type of patching is because most consoles cannot handle lighting fixtures with multiple instances of the same type of control (multiple color or intensity systems). Imagine a single lighting fixture with control of four intensities, three sets of RGBW and four different strobe channels! Utilizing palettes/presets, groups, effects and copying tools becomes very complex when everything is combined in one fixture type. Breaking the units down into segments makes them work better with the console functions and tools. However, with a large number of these units on stage, this can be an unimaginable amount of fixture numbers to deal with. It also can be quite a mess when trying to map fixtures onto a layout or magic sheet view.
Luckily, some console manufacturers have implemented multi-part fixtures into their systems. These allow you to patch the above example as one fixture with multiple segments. So instead of patching as fixtures 100-103 you would simply patch the unit as 101. Then you define it as having a specific number of “parts” so that you can control it as 101 (the entire fixture), 101.1 (the first segment), 101.2 and 101.3 (the other two segments). The desk understands that each segment is unique, but keeps them connected to a single fixture number or instance within the desk. This method also helps with layout and magic sheet views as each fixture can be plotted as a single unit.
Customizing Fixtures
The patch window of your lighting console not only allows you to map console fixture numbers to DMX routing, but it also often provides methods to customize fixture settings. The most common is related to positional information. You can often invert or swap pan and tilt controls. This is very handy when you have fixtures in different orientations within your rig. Although these settings can also be assigned at each fixture, it is generally better to set them in the patch. Often you can also limit pan or tilt ranges to ensure that fixtures can only point within a specified range (note that they will still move their full range when calibrating). You may also be able to change the dimming curve and/or set defaults or limits for individual parameters.
Another useful feature within the patch is labeling. Most consoles allow you to label fixtures and add notes. I find this very useful to indicate the location of a fixture (Red Truss, Floor SR or FOH). Usually you can view this same information in other windows on your desk to easily know not only the fixture number, but also the location. Notes fields can be used to enter information for technicians or other important details.
Automating Patching
With the rising acceptance of RDM (Remote Device Management), there are now some methods to automate some of the patch process. However, it is important to understand the limitations along with the benefits. Many consoles and fixtures have not yet fully implemented RDM, so the full functionality may not be possible on your desk. However, RDM does provide the ability to discover devices attached to a console, identify their type and mode and change their DMX address and other settings. With these abilities, you can have the consoles and fixtures communicate with each other to automatically create the patch for you, although you will have to interact with the system to identify which fixtures match up with your specific console fixture numbers. This will eliminate the process of learning and setting DMX addresses and could save time.
Patch Perfect
Automated lighting programmers must understand DMX systems and how to patch their specific console. Without this basic ability, there will never be any communication between the console and the fixtures. By understanding what it takes to patch, you can quickly build a fixture list and patch accordingly for your rig. As always, be sure to read your console user manual to ensure you fully understand how it handles patching and the associated options. With your patch in place, then you are ready to start programming and on your way to a wonderful show.
