Within Titan, each and every single item has an Id - simply an integer number which is this item's unique identifier. This can be used to refer to a specific item by calling this object with its id.
Usually, each id is set by Titan itself - you have no means - and no reason - to alter a particular item's id. Also, that's why you will use the titanId in macros only in rare cases: there is no practical way to find the titanId of a specific item, and it might be different in the next show. However, there are some reserved IDs which might be a good guess for the master IDs in new shows. As you can see below this is not guaranteed, in particular across versions – the IDs have changed from v10 to v11/v12, and then again to v13 (these are at least valid until Titan v15, tested June 2021):
|Titan Id v10||Titan Id v11, v12||Titan Id v13/14/15||Handle||Description|
|1604||1609||1609||RateGrandMaster||Rate Grand Master|
|1606||1611||1611||SizeGrandMaster||Size Grand Master|
|1607||1612||1612||BPMMaster:0||BPM Master 1|
|1608||1613||1620||RateMaster:0||Rate Master 1|
|1609||1614||1621||SizeMaster:0||Size Master 1|
|1611||1616||1613||BPMMaster:1||BPM Master 2|
|1612||1617||1623||RateMaster:1||Rate Master 2|
|1613||1618||1624||SizeMaster:1||Size Master 2|
|1615||1620||1614||BPMMaster:2||BPM Master 3|
|1616||1621||1626||RateMaster:2||Rate Master 3|
|1617||1622||1627||SizeMaster:2||Size Master 3|
|1619||1624||1615||BPMMaster:3||BPM Master 4|
|1620||1625||1629||RateMaster:3||Rate Master 4|
|1621||1626||1630||SizeMaster:3||Size Master 4|
|1616||BPMMaster:4||BPM Master 5|
|1617||BPMMaster:5||BPM Master 6|
|1618||BPMMaster:6||BPM Master 7|
|1619||BPMMaster:7||BPM Master 8|
(found by scrutinizing showfiles after uncompressing)
There is a website which retrieves titanIds from your show if called on the same computer where Titan PC suite (and Web API) are running: http://www.avolites.de/downloads/miditoweb/gettitanids.htm, see also Titan IDs.
ASSUMPTION (derived from some examples)
In order to call an item by its id, you simply pass its titanId as handle, without any other identifiers:
<!-- function definition: Void Masters.TapTempo(Handle handle, DateTime panelTimeStamp) --> <step>Masters.TapTempo(1607, Math.GetCurrentTimeStamp())</step>
Further explanation from http://forum.avolites.com/viewtopic.php?f=20&t=5731#p20666:
For a given show file the IDs will remain the same once they are allocated. The IDs may have seemed fixed however this was only because they are usually about the first things to be allocated so might often end up with the same numbers (1600 is the start of the non-fixed IDs). There was an intention when rate and BPM masters were added that at some point we would likely want to allow for any number of masters to be created so for this reason the software was written to allocate them dynamically. These masters were added several versions before WebAPI and macro documation was released so this wasn’t a consideration at the time. Perhaps a way can be added which can allow you to reference masters properly and reliably in macros in future versions.
When importing, unless you are mapping to something that already exists in the current show, new Titan IDs will be allocated; this prevents IDs from clashing.