AbstractThree currently available concurrent language systems, Pascal‐Plus, occam and Edison, are used to implement a controller for a robot arm. The robot arm allows real parallelism of operation within the movements of the arm. The feasibility and restrictions placed upon the resultant solution for each of the language systems is then analysed and discussed. A Petri‐net solution is also presented for the generalized problem and it is shown that each of the solutions is a different folding of the general