Numerical controller including means for checking execution status of program

A numerical controller that controls a machine based on a program, the numerical controller comprising:

• a processor configured to:
• receive manual instructions for manually advancing and manually reversing execution of the program;
• control operation of the machine by sequentially executing the program in response to the manual instructions;
• and
• identify a block in the program execution of which is about to be executed in response to the manual instructions, based on an attribute of the identified block, and output a notification prior to execution of the identified block,
• wherein:
• a) in response to the block being identified as an edited block, output a first sound notification or a first vibration notification to an operator of the machine,
• b) in response to the block being identified as an specified block, output a second sound notification or a second vibration notification to the operator of the machine,
• c) in response to the block being identified as including a switching point to another block, output a third sound notification or a third vibration notification to the operator of the machine, and
• d) in response to block being identified as a prohibited block in which the reversing execution of the program is prohibited, output a fourth sound notification or a fourth vibration notification to the operator of the machine and control the machine to prohibit reverse operation,
• wherein the first sound notification, the second sound notification, the third sound notification and the fourth sound notification are distinct from one another, and
• wherein the first vibration notification, the second vibration notification, the third vibration notification and the fourth vibration notification are distinct from one another.