A system and method for control of prescription drug packaging and dispensing machines located in an in-patient health care facility including centralized control and enhanced communication between system components. Delay and errors in processing item data in the prescription dispensing system are reduced by using concise ID data incorporated into each canister memory chip and storing canister contents data elsewhere. Canisters are configured in a pharmacy using interchangeable parts. Data being processed is synchronized by a combination of user tokens (who), data identifiers (what), and unique Ids for the entities in the system (where). The foregoing combination enables substantial efficiency improvements and error reduction.