Mitsubishi Electric MELSEC iQ-R-R00CPU - Page 608

606
37 FUNCTIONS
Functions
different
(modified or
restricted) from
Part 2
Constant scan • In the standby system, system switching when the system is powered off, a
hardware failure has occurred, or a tracking cable has a failure may
generate a continuation error due to the excess of constant scan time.
• The constant scan function is invalid for the standby system.
Page 662 Constant Scan
Output mode setting of STOP to
RUN
The safety output (SA\Y) for the safety output device (SA\Y) is off, regardless
of this setting. If the value is changed with a device test or others while the
CPU module is in the STOP state, the value will be applied when the status of
the CPU module changes from STOP  RUN.
Page 676 Safety output
(SA\Y)
Interrupt
function
Internal timer
interrupt
When the systems are switched during time measurement of I28 to I31, the
time measurement is interrupted and the new control system starts the time
measurement from 0.

Interrupt period
setting
The interrupt pointer (I) cannot be used in safety programs. Also, the following
cannot be used in standard programs.
• Inter-module synchronous interrupt (I44)
• Multiple CPU synchronous interrupt (I45)
• High-speed internal timer interrupts (I48, I49)
MELSEC iQ-R CPU
Module User's Manual
(Startup)
Multiple
interrupt
function
Safety cycle processing is performed as a higher priority interrupt than other
processing, and therefore even when set to "Enable" in the multiple interrupt
settings, interrupts will never occur during safety cycle processing.

Clock
function
Clock setting When setting clock data for the Safety CPU at the "Set Clock" window of the
engineering tool, "All Stations Specified" cannot be selected as an execution
target.

Time
synchronization
The time of the standby system is synchronized with the time of the control
system. The time setting using the time setting function (SNTP client) is
available only for the control system.

System clock After system switching, SM420 (User timing clock No.0) to SM424 (User
timing clock No.4) remain off on the new control system CPU module.
To use SM420 to SM424 on the new control system CPU module, execute
the DUTY instruction again.

Writing data
to the CPU
module
Online change
(ladder block)
• When the online change (ladder block) is performed on the CPU module in
one system, the change is also reflected on the CPU module in the other
system.
• Online changes (ladder block) are not possible in safety programs.
• Safety program files, safety global label setting files, and standard/safety
shared global label setting files cannot be changed online. However, if
standard/safety shared labels inside standard programs are edited,
standard programs can be changed online.
• If a disconnection, power-off, or reset of the CPU module is detected while
the program restoration information is being written, the processing will be
suspended and a message will be displayed. If the processing is
suspended by a disconnection, click the [Retry] button in the message after
reconnecting cables. If the processing is suspended by power-off or reset,
login to the user authentication function is disabled. Log in to the function
and write data again to the programmable controller.
Page 662 Online
Change
Function Description Reference