Here the description of the rites from the 1962 Rituale Romanum for the forty hours adoration
sanctamissa.org/en/resources/books-1962/rituale-romanum/25-the-sacrament-of-the-holy-eucharist-forty-hours.html
Only the beginning and ending rites are described, without prescription what should be done during the 40 hours
Here is the Canon Law referring to the liturgical books, and expecting only suitable number of adorers.
Can. 941 §1. In churches or oratories where it is permitted to reserve the Most Holy Eucharist, there can be expositions with the pyx or the monstrance; the norms prescribed in the liturgical books are to be observed.
§2. Exposition of the Most Blessed Sacrament is not to be held in the same area of the church or oratory during the celebration of Mass.
Can. 942 It is recommended that in these churches and oratories an annual solemn exposition of the Most Blessed Sacrament be held for an appropriate period of time, even if not continuous, so that the local community more profoundly meditates on and adores the eucharistic mystery. Such an exposition is to be held, however, only if a suitable gathering of the faithful is foreseen and the established norms are observed.
Can. 943 The minister of exposition of the Most Blessed Sacrament and of eucharistic benediction is a priest or deacon; in special circumstances, the minister of exposition and reposition alone without benediction is the acolyte, extraordinary minister of holy communion, or someone else designated by the local ordinary; the prescripts of the diocesan bishop are to be observed.
vatican.va/archive/ENG1104/__P3C.HTM
Here is the most current (2001) directives including:
Eucharistic Adoration (164-165)
vatican.va/roman_curia/congregations/ccdds/documents/rc_con_ccdds_doc_20020513_vers-direttorio_en.html
also referring only to the liturgical books.
In a nearby parish there is perpetual adoration in a separate chapel. There is the Eucharistic lamp (candle renewed daily) and the chapel is accessible only by code outside of the most frequented hours. In the wee hours the rule is if someone leaves the chapel alone he or she covers the monstrance. If someone finds it covered he may or may not uncover it.
This is the process how we think about the Eucharist and Jesus presence in that: is it mysterium fidei only surrounded with delicate rubrics; or something closer than that, food for us, our friend, helper, fortress, open to us at any time.