Abstract: A method of and apparatus for detecting the operative status of each of a series of remote stations connected to a main control in an elevator system includes a step or apparatus for causing the main controller to develop a roll call signal which is transferred to a first of the series of remote stations, transmitting an operative status reply signal from the remote station to the main controller if the remote station is functional following receipt of the roll call signal by the remote station, transferring the roll call signal to a next of the series of remote stations after the reply signal is sent to the main controller, and continuing to transmit an operative status reply signal until each of the remote stations has done the same, if operative.

Abstract: An elevator control utilizing a data processor and which is sequentially responsive to independent program blocks. The control includes a central processing unit, programed read only memory and random access memory, with input and output circuits for interconnection between the control, the elevator, elevator drive and the structure in which the elevator operates. The memory has a capacity to store information for elevator systems and structures with a wide variety of parameters. Specific addresses in the memory are assigned for the input information and for elements of status information which provide for interaction between different portions of the program. The assigned addresses are common to all elevator controls, enabling use of standard program blocks and minimizing the original design work required for each control.