TechWhirl (TECHWR-L) is a resource for technical writing and technical communications professionals of all experience levels and in all industries to share their experiences and acquire information.
For two decades, technical communicators have turned to TechWhirl to ask and answer questions about the always-changing world of technical communications, such as tools, skills, career paths, methodologies, and emerging industries. The TechWhirl Archives and magazine, created for, by and about technical writers, offer a wealth of knowledge to everyone with an interest in any aspect of technical communications.
The phrase "to trigger" is an infinitive. Infinitives are the "to" forms of
verbs and may function as nouns, adjectives, or adverbs. In your first
example sentence the infinitive "to trigger" acts as an adverb. (You can
configure an alarm to trigger.) In your second example sentence, you
created an infinitive phrase (to trigger an alarm). In this case, the
infinitive phrase acts as an adjective phrase (or verbal phrase) modifying
the noun software.