Per the PHB, 10th printing...
DISINTEGRATE
6th-level transmutation
Casting Time: 1 action
Range: 60 feet
Components: V, S, M (a lodestone and a pinch of dust) Duration: Instantaneous
A thin green ray springs from your pointing finger to a target that you can see within range. The target can be a creature, an object, or a creation of magical force, such as the wall created by wall offorce.
A creature targeted by this spell must make a Dexterity saving throw. On a failed save, the target takes
10d6 + 40 force damage. The target is disintegrated if this damage leaves it with 0 hit points.
A disintegrated creature and everything it is wearing and carrying, except magic items, are reduced to a pile of fine gray dust. The creature can be restored to life only by means of a true resurrection or a wish spell.
This spell automatically disintegrates a Large or smaller nonmagical object or a creation of magical force. If the target is a Huge or larger object or creation of force, this spell disintegrates a 10-foot-cube portion of it. A magic item is unaffected by this spell.
In looking at the text, as a Magical Object...an Arcane Canon, is not automatically disintergrated.
Since most people, (docbadwolf excepted), are not ruling the Arcane Canon as a Magic Item, it is not immune to the spell.
The Arcane Canon getting a DEX Saving Throw at +0 should be the result, based off the text.