An extended programmable machine controller (PMC) which is disposed outside a numeric controller (1) and connected to a main body PMC inside the numeric controller (1). Switch control means (12) switches a ladder program (13) for controlling a mechanism portion B (62) and a ladder program B (14) for executing pseudo-wise the operation of the main body PMC (2). Accordingly, debugging or operation can be made by the extended PMC (10) alone using the ladder program B (14) even when the main body PMC (2) is not constituted.
