Router buses and output selectors are easiest to use when the inputs and outputs you need are numbered sequentially. If you have five VTRs on inputs 10−14, you can easily use a router bus, but if your VTRs are on inputs 10, 20, 30, 32 and 90, it is more difficult.
Group Map files are the answer to this.
UPDATE – router Group Map files no longer need to be text files external to the Helm panel the group map is now saved in the .helm panel file just like all other properties. Apart from this change the syntax of group maps remains the same.
A Group Map file is a plain text file that defines named “groups” of input and output signals. For example:
; This is an example router group map file [InputGroups] VTR=10, 20, 30, 32, 90 SERVER_A=40, 42, 44, 46, 48 SERVER_B=41, 43, 45, 47, 49 SERVER=SERVER_A,SERVER_B [OutputGroups] TX=11, 12, 16, 19, 33 LEGALIZER=20-23
Shortcuts allow you to specify a range of inputs (“20-23” is equivalent to “20, 21, 22, 23”), and use an optional step value with the range (so “20-40:5” is equivalent to “20, 25, 30, 35, 40”). You can also use the name of previously defined groups to make composite groups, as in SERVER=SERVER_A,SERVER_B above.
Comment lines beginning with a semicolon are ignored, but comments cannot be added to the end of other lines.
You can assign any input group to a router bus (either in HELM Designer, or at run time). The required inputs are shown on the buttons. FirstInput selects which signals within the group are shown. If the group has fewer inputs than the number of buttons on the router bus, the remaining buttons are hidden. Also, if router buses are grouped using the RouterBusGroup property, they all update together.
See a screencast with an example here:
_BASE group and router remapping. [V3.4.5]
It’s possible to globally remap all router inputs and outputs using the special group “_BASE” that can be defined in the group map file. The _BASE group (if present) represents all the inputs (or outputs) that are to be used for the router.
For example, take a 128×128 router, where only sources 120..127 are required.
Now, router input ‘1’ in helm is treated as physical router input 120. This is applied in addition to any ‘normal’ groups , so sources can effectively get mapped twice.
[INPUTGROUPS] _BASE=120-127 CAMERAS=0-3 ; Because of _BASE, this means Cameras are 120 to 123 VTRS=4-7 ; ... and VTRs are 124 to 127
You can also add a _BASE group for outputs in the same way