Data Unit For Writing; Available Number Of Steps For Writing - Mitsubishi Electric M800VW Series Manual

M800V/M80V Series PLC Development Manual
5 Peripheral Development Environment (GX Works2)
5.6 Developing Simple Project

5.6.8.4 Data Unit for Writing

The following table shows the available data units for the ladder program writing during RUN and specifications of an upper
limit of each writing are as follows. Ladder blocks are written at the conversion after edited. When the ladder program writing
during RUN is executed from the ladder edit screen, either the single block or the multiple blocks will be written in the ladder
program. The writing method to be executed is automatically determined based on the standard stated in (*1) below the table;
therefore, the method cannot be selected by users. The ladder program cannot be written to PLC on a file basis with the
operation such as selecting [Online] - [Write to PLC].
[Available data units for the ladder program writing during RUN]
Data units for writing
Ladder program writing during RUN
of single block
Ladder program writing during RUN
of multiple blocks(*1)
Ladder program writing during RUN
in file units
(*1) For GX Works2, when you edit the definition of FB where multiple instances exist in a single program, the ladder pro-
gram writing during RUN of multiple blocks will be applied. When you add or delete FB instance, the ladder program writ-
ing during RUN of single block will be applied.
For GX Developer, when you edit the definition of FB where an instance exists, multiple-block writing in ladder program
during RUN will be applied. When you add or delete FB instance, single-block writing in ladder program during RUN will
be applied.

5.6.8.5 Available Number of Steps for Writing

Ladder program writing during RUN is available until the total number of steps needed for executing the sequence program
set in the parameter reaches the maximum number of steps of the program execution area. (For the maximum number of
steps in the sequence program execution area, refer to the "PLC Programming Manual".)
Note that when RUN write in high-speed processing is enabled, the number of steps in the sequence program execution area
will be as shown below.
 When the multi-project function is disabled
The maximum number of executable steps in a high-speed processing is fixed to 4,000. If the number of steps exceeds 4,000,
NC will show an alarm and RUN write will be disabled.
In addition, the maximum number of executable steps in a main processing program decreases by 8,000 steps.
The following shows the relation between the settings and available number of steps for RUN write.
[Settings and available number of steps]
Setting of "Enable ladder program
writing during RUN"
High-speed pro-
Main process
cess
ON ON
OFF ON
OFF OFF
GX Works2
○
512 steps
○
64 blocks
Total 1024 steps
×
Number of steps available for execution
High-speed processing program
High-speed processing program ≤ 4,000
steps
(Total number of steps in high-speed processing program and main processing pro-
gram) ≤ Number of steps in execution area
145
Built-in PLC (built-in edit
GX Developer
function)
○
512 steps 512 steps
○
64 blocks
Total 1024 steps
×
Main processing program
Main processing program ≤
(Number of execution area steps - 8,000
steps.)
○
×
×
IB-1501614-B