CNC Program Comment Introduction
One or more program comments and messages can be included within the program body as separate blocks, or as parts of an existing block, mostly in cases when the message is short. In either case, the message must be enclosed in parenthesis (for ASCII/ISO format).
CNC Program Comment Examples
Example – 1
N330 M00 (REVERSE PART)
Example – 2
N330 M00 (REVERSE PART / CHECK TOOL)
Example – 3
(REVERSE PART / CHECK TOOL)
CNC Program Comment Details
The purpose of a message or comment in the program is to inform the machine operator of a specific task that must be performed every time program reaches the stage of processing where such message appears. Comments are also useful for understanding the program at a later date and can be used for documenting the program.
Typical messages and comments relate to information about setup changes, chip removal from a hole, dimensional check, cutting tool condition check and many others. A message or a comment block should be included only if the required task is not clear from the program itself – no need to describe what happens in each block. Messages and comments should be brief and focused, as they occupy a memory space in the CNC memory.
From practical perspective, short series of messages and comment blocks can be provided at the beginning of each program, to list all significant drawing information and cutting tools required for the job.
O1001 (SHAFT – DWG B451)
(SHAFT TOOLING – OP 1 – 3 JAW CHUCK)
(T01 – ROUGH TOOL – 1/32R – 80 DEG)
(T02 – FINISH TOOL – 1/32R – 55 DEG)
(T03 – OD GROOVING TOOL – 0.125 WIDE)
(T04 – OD THREADING TOOL – 60 DEG)
N1 G20 G99
If the available memory space of CNC unit is limited, using comment blocks in this manner may prove impractical. It will be better if the messages and comments are listed in proper setup and tooling sheets, with all required details.