Precautions For Dedicated Instructions; Organization Of The Dedicated Instruction Sections - Mitsubishi Electric MELSEC-L SERIES Basic User Manual

15.3

Precautions for Dedicated Instructions

This section describes precautions for using dedicated instructions.
(1) When changing data specified by dedicated instructions
Do not change any data (e.g. control data) until execution of the dedicated instruction is completed.
(2) When the dedicated instruction is not completed
Check that "Online" has been set under "Mode" in the network parameter window. Dedicated instructions cannot
be executed during offline.
(3) Securing service process time
When accessing a programmable controller on another station using a data link instruction during the Ethernet
diagnostics, execution of the instruction may be delayed. Take the following measures to execute the data link
instruction after the Ethernet diagnostics.
• Execute the COM instruction.
• Reserve time for a communication process for 2 to 3 ms. Use a programming tool for the setting.
Project window
"PLC System" tab
(4) Specifying the first argument of a dedicated instruction (Un)
The first argument of a dedicated instruction (Un) can be also specified with double quotation marks (" ").
15.4

Organization of the Dedicated Instruction Sections

For the organization of the dedicated instruction sections, refer to Page 13.
198
[Parameter] [PLC Parameter] "Service Processing Setting" under the