Single-shot rack manufacturers and suppliers Evolved Pyrotechnics and Monetti ishot Plug & Fire offer reusable tube bases that single-shot tubes can snap into. The bases can be pre-wired in the rack to an attached firing system module, making setup a breeze — just snap in the tubes and hook up the module.
The idea of pre-wiring the tubes, though, introduces complexity at the time of assigning firing system addresses if the tubes are at varying fixed angles. For example, if a fan rack of 13 posts is pre-wired to pins 1-13 of a module, then if the show calls for a smaller fan of 5 posts shot from the 13-post rack, the pin addresses of the 5 shots must match the pre-wired pins of the specific 5 used posts, which may be, for example, 1, 4, 7, 10, 13. The firing system addresses of the shots in the show may therefore not be sequential — there may be gaps in the sequence of used pins, such as the gap between pin 1 and pin 4 of the 5-fan.
Figure 1 – Rack with fixed angle posts and i-shot bases that can be pre-wired
Procedures that assign firing system addresses by “filling down, and incrementing” in a column of addresses aren’t well suited for angled tubes with pre-wired pins because the procedures cannot simply assign sequential pins. They need to skip over the gaps and assign only the right pins that correspond to the tube housings at the correct angles. By contrast, constraint-based addressing procedures like in Finale 3D have no difficulty skipping over gaps to satisfy the constraints.
To assign firing system addresses for racks with pre-wired pins using Finale 3D, you need to make two configuration adjustments:
- In your rack definition, select one of the “pre-wired pins” constraints.
- In the addressing dialog or blueprint add two constraints to bind the modules with the racks one-to-one.
The first configuration adjustment is part of the rack definition. If you do “Racks > Create rack” or right click on a rack in your effects list, the dialog shown in Figure 2 presents several options for pre-wired pins.
Figure 2 – Options for configuring a rack for pre-wired pins
Select the option that matches your wiring. If the pins start with the first tube of the first row, then the second tube and so on to the end of that row, and then continue incrementing into the next row, that’s the ‘Sequential by rows’ option. If the pins go across the rows, starting with the first tube of the first row, then the first tube of the second row, etc., and then eventually wrapping around to the second tube of the first row, that’s the ‘Sequential across rows’ option. The ‘Sequential for each row’ option begins every row with the first pin number, counting up in each row to the end of the row. This third option applies if each row is bound to a firing system slat or module of its own. The ‘Sequential by rows, half and half’ option is just like ‘Sequential by rows’ except that the pins start over with 0 on row N/2 for N = number of rows. The ‘Sequential across rows, half and half’ option restarts the pin sequence with 0 after getting half way through all the rows. Diagrams of all nine options are shown in Pre-wired pin options.
The ‘Specified by Custom Part Field’ option and ‘Specified by Custom Rack Field’ option give you the ability to define the pin sequence arbitrarily, including the interesting possibility of creating a rack with just one tube and having an arbitrary pre-wired pin for that tube, which can be used to pre-wire every tube in a shoot site arbitrarily, as may be convenient for a re-usable rack layout in a venue with a built-in firing system pre-wired to every tube in the site.
To use these two options, fill in the Custom Part Field or Custom Rack Field of the rack with a comma separated list of the pin numbers that correspond to the tube indexes listed sequentially by rows, left to right. The difference between Custom Part Field and Custom Rack Field is that Custom Part Field is an intrinsic property of the rack definition, whereas the Custom Rack Field is a property of each rack instance.
For example, if you insert 30 instances of the rack being defined, all of them will have the exact same Custom Part Field. You can edit the Custom Part Field of the rack in the effect row representing the rack in the effects window. If you wanted each of the 30 instances of same rack definition to have a different specification of its pin order, you would use the Custom Rack Field, which you can edit in the table rows representing the racks at the bottom of the rack layout window.
The second configuration adjustment is in the addressing dialog or addressing blueprint dialog that controls the manner in which the firing system addresses are assigned. When you do the command “Addressing > Address show” the dialog shown in Figure 3 is presented.
Figure 3 – Binding modules to racks requires two constraints
You need to add a constraint to restrict each module to a single Rack; and also a constraint to restrict each rack to a single Module. The combination of those two constraints binds the modules and racks together one-to-one, which is correct if your modules are physically attached and pre-wired to the racks.
Section 2 of this dialog, controlling the order of assignment, does not need to follow any specific order for pre-wired pins. Because the addressing procedure is constraint-based, the constraints guarantee the pre-wired pins will match the correct firing system addresses.
Figure 4 – Pre-wired pins may force gaps in the pin addresses, such as from 01 to 03
Figure 4 shows an example of two racks each with two rows of 5 fanned out tubes, running horizontally as oriented in this picture. The center tubes (03 and 08 in both racks) are aiming straight up; the tubes on the left (05 and 10) are aiming -30 degrees to the left; the tubes on the right (01 and 06) are aiming 30 degrees to the right. The tubes in between are aiming -15 degrees and 15 degrees.
In this example the show has 16 shots, which leaves 4 tubes empty, but not just any 4 tubes. The show has only 1 shot at 15 degrees, and only 3 shots at -15 degrees. It has 4 shots at all the other angles. Thus the four empty tubes — and the four unused pins — correspond to the missing angles.