Numerical controller including tool retracting function for avoidance of interference

A numerical controller controlling a machine tool, the numerical controller comprising:

• a retraction block determination condition setting unit configured to set a condition for selecting as a retraction block a block in a machining program that moves a tool in an opposite direction along a command movement path when machining is suspended during machining operation and the tool is retracted;
• a determination unit configured to determine, when the machining is executed to perform the machining program, whether or not a decoded block in the machining program is the retraction block that satisfies the condition set by the retraction block determination condition setting unit;
• an executable format data reading unit configured to read executable format data resulting from decoding of the block determined to be the retraction block by the determination unit;
• an end point coordinate position reading unit configured to read an end point coordinate position indicated in the block determined to be the retraction block by the determination unit;
• a memory unit configured to store the read executable format data and the end point coordinate position;
• and
• a tool retracting unit configured to move, when a tool retraction command is input, the tool from a current tool position to the end point coordinate position of the retraction block stored in the memory unit, then to reverse a moving direction for the executable format data of the retraction block stored in the memory, and to execute the executable format data in order to retract the tool.