Precautions - Mitsubishi Electric MELSEC iQ-R-R00CPU User Manual

Precautions

Operation at power-on
When the RUN/STOP/RESET switch of the CPU module of each system is set to the RUN position and both systems are
powered on, the control system CPU module starts in the STOP state and switched to the RUN state after reflecting the
tracking data is completed in the standby system CPU module. (The same operation is performed when one system is
powered on while the other system is waiting for the start-up of the other system.)
Since the operating status of the CPU modules between the control system and the standby system do not march until the
control system is switched from the STOP state to RUN state, the BACKUP LED flashes.
When the time of the initial processing and that of the initial processing (when switched to RUN) of the standby system CPU
module are longer than those of the control system CPU module, the control system CPU module may not be immediately
switched to the RUN state after power-on.
Device data used by the new control system CPU module
After system switching, the new control system CPU module starts operations by using the device/label data received in
tracking transfer. The following table shows device/label data used by the new control system CPU module by tracking data
receive status at system switching.
Device/label initial value
Not set
Set
Data capacity for tracking transfer
Up to 1M words of device/label data can be transferred in one scan. Set the tracking data capacity within 1M words.
If the data capacity exceeds 1M words, standard global devices/standard local devices/standard global labels/standard local
labels are not transferred in the scan. In this case, check which tracking trigger turned on in the event history of the
engineering tool and set the tracking data capacity within 1M words.
n scan
ON
Block 1 tracking trigger
OFF
ON
Block 2 tracking trigger
OFF
ON
Block 3 tracking trigger
OFF
No.1
Tracking data 1M words
Tracking capacity exceeded
Even though the size of the tracking data to be transferred is 1M words or less, the size of the data may become larger than
1M words depending on the label type or data type to be used after the data or all the data is converted with the engineering
tool. When configuring "Tracking Setting" with the CPU parameter, click the [Size Calculation] button in "Detailed setting" of
"Device/Label Detailed Setting" to check if the size of the tracking data is 1M words or less and transferred in one scan. (
Page 630 Detailed setting)
To reduce the size of the tracking data, consider the following.
• Exclude devices/labels that are not required to continue the system operation.
• Divide the tracking data into multiple blocks to transfer the data in multiple scans.
No tracking data received
Operation starts based on the latched device/label data.
Operation starts based on the device/label data that is
set with device/label initial values.
n+1 scan n+2 scan
No.1 No.1
No.2
No.3
No.3
Tracking data received once at least
Operation starts based on the device/label data that is
transferred from the old control system.
When the synchronous tracking mode is used as a
tracking mode, the data in the old control system at the
final scan start is used by the new control system.
n+3 scan
No.1
No.2
37 FUNCTIONS
635
37.2 Tracking Transfer
37