A system for the remote monitoring of vending machines and for automatically communicating conditions at the vending machines to a central computer complex is described. Each vending machine is provided with a microprocessor which monitors and stores data within that machine and transmits the data to the central computer complex either immediately or at scheduled call-in times. The distributed logic between the vending machine microprocessors and the central computer complex provides various alarm function signals and aids in inventory control and efficient route planning for the supply and maintenance of the machines. In a preferred embodiment the data is transmitted between the central computer complex and each vending machine over telephone lines.