Programming instructions

110
Important: The PLC will only hold the first 16 characters of comments. The rest
of the comment will be truncated.
If the programmer wants to document the program as the program is written, it is
possible to have comments and one other form of documentation enabled at the
same time. Go to the Tools pull-down menu, select Options, and click the box
next to “Continues during Command Write” under the Device Comment Input
heading. As devices are entered into the program, GX-Developer will prompt for
a comment.
Downloading comments
Downloading comments is very easy with the FX3U. Unlike with some of our
other processor lines, there is no need to set comment ranges. It is only
necessary to set comment capacity in parameters and download!
Setting comment capacity
Comment capacity is set in PLC Parameters, under the Memory Capacity tab.
The programmer allocates a number of blocks. Each block allows the
programmer to comment 50 unique devices. Thus a comment for X0 is one
device, even if X0 appears 15 times in the program. Unlike with some of our
other processor lines, blank comments do not count towards the devices
comment count.
Comment blocks consume 500 steps of programming space.
15.2 Statements
Statements, also known as circuit comments, provide a description of the
purpose for a whole rung. A typical statement would be: “This rung waits until
the counter reaches 20 and opens the gate”.
Set number of comment blocks –
indicates how many devices can
be commented
How many steps remain for
programming?