CJ2 CPU Unit Software User's Manual - CIP ETI

10 CPU Unit FunctionsNote The above times are the same as the synchronous processing time minus the normal processing time performedduring that time.Internal processing for normal cycle timeSynchronous unitoperation enabled(2) (2) (1) (2) (2) (1)Synchronousoperation cycleSynchronousoperation cycleSynchronous unitoperation disabledInternal processingfor normal cycle time Scheduled Interrupt Tasks 0 and 1 DisabledIf synchronous unit operation is used, scheduled interrupts 0 and 1 cannot be used to execute interrupttasks. Thus, scheduled interrupt task 0 (interrupt task 2) and scheduled interrupt task 1 (interrupttask 3) cannot be used. Interrupt task 2, however, is used as the synchronous interrupt task. Restrictions for Interrupt Control InstructionsThe MSKS, MSKR, and CLI instructions cannot be used in the synchronous interrupt task. The DIand EI instructions can be used. Restrictions for Timer Instructions• The following restrictions apply to the TIM/TIMX, TIMH/TIMHX, and TMHH/TMHHX instructions.• The timers will not operate correctly if the cycle time exceeds 100 ms.• If one of these timer instructions is used in a task that is stopped or is not executed because itis jumped by a JMP, CJMP, or CJPN instruction, there will be the following error in the timerTIM/TIMX: −10 msTIMH/TIMHX: −10 msTMHH/TMHHX: −1 ms• The timer PVs cannot be accessed accurately. Restrictions on Using Instructions in Interrupt Tasks When High-speedInterrupt Function Is EnabledIf using the synchronous unit operation function is enabled, the high-speed interrupt function will beunconditionally enabled in the PLC Setup. Thus, some instructions, such as network communicationsinstructions, cannot be used in any interrupt tasks, including the synchronous interrupt task.For details, refer to 10-2-6 High-speed Interrupt Function. Other Restrictions When High-speed Interrupt Function Is Enabled• Background processing cannot be used in interrupt tasks.• The data in the following Auxiliary Area words will not be valid: A440 (Maximum Interrupt TaskProcessing Time) and A441 (Interrupt Task with Maximum Processing Time).• The increase of the cycle time cause by using EtherNet/IP tag data links will be even longer. Mounting Location for Synchronous UnitsIncrease in normal cycle timecause by synchronous unitoperationSynchronous Units must be mounted on the CPU Rack. They cannot be mounted on ExpansionRacks.10-90 CJ2 CPU Unit Software User’s Manual