The $580,000 automated storage and dispensing machine is 1.5 miles long and holds 850 shelves.
It uses lasers and barcodes to identify medicine.
Dr Tracey Boyce, Southern Trust director of pharmacy said the new robot allowed staff to spend more time on wards with patients.
Dr Boyce said: "The robot is fast and extremely accurate at selecting pharmaceutical products. For example, it will collect together all the items required for each hospital ward's weekly stock order, delivering them directly into the transport trolley, ready to go to the ward.
"Overnight, the robot reorganises the stock inside it to ensure that the storage space available is maximised for the next day.
"It also allows staff to be released from the pharmacy dispensaries so that they can be based on hospital wards, working with patients to ensure the safe, effective and efficient use of medicines."
The robot was the first to be installed in any hospital in Northern Ireland and has been operational since last April. Dr Boyce said there were challenges in the first few weeks as pharmacists grew accustomed to their mechanical colleague.
"Things have settled down now and we have almost forgotten about the old system already," she added.
Dr Boyce also said there were plans to extend the new IT system on to the hospital wards.