The present invention relates to improvements in a numerical controller which is equipped to perform sequence control of a heavy-current circuit for a machine tool.
The function of carrying out the sequence control of a heavy-current circuit for a machine tool can be provided by a data processing unit of a numerical controller (which function will hereinafter be referred to as a PC function) to reduce the cost and the space requirements of an NC machine tool, and numerical controllers equipped with the PC function have recently become popular. In conventional equipment of this kind, however, since a PC programmer for entering into an NC system a PC program into the NC system in order to perform the PC function and for correcting and confirming the PC program is not provided in the NC system, an expensive and bulky PC programmer unit must be separately provided.
To avoid this, there has been recently proposed a numerical controller which performs the PC programmer function to permit debugging of the PC program or the like without using such a separately provided unit, but since it uses one control panel for operating both of the NC system and the PC programmer, it is likely to incur erroneous operation, and hence for a manipulation.