CJ2 CPU Unit Software User's Manual - CIP ETI

1 Overview1-1-2 CJ2 CPU Unit FeaturesFast, with Large Memory Capacity High-speed ProcessingHigh-speed processing is possible for basic instructions (0.016 μs min. for CJ2H and 0.04 μs min.for CJ2M), special instructions (0.05 μs min. for CJ2H and 0.06 μs min. for CJ2M), and immediaterefreshing (0.99 μs min. for CJ2H and 1.26 μs min. for CJ2M). Large Program CapacityThe CJ2 CPU Units provide a large program capacity of up to 400 Ksteps. Special Function Block Definition Area (CJ2M Only)With a CJ2M CPU Unit, a special area called the FB Program Area is provided to store functionblock definitions. (The FB Program Area holds 20K steps.) This allows you to use function blocks tomake program components and structures from previous programs while reducing the usage of theUser Program Area. And any function block definitions that would exceed the FB Program Area arestored in the User Program Area. Large Data Memory CapacityThe CJ2 CPU Units provide a large EM Area capacity of up to 800 Kwords (25 banks). Up to 128 Cyclic TasksThe user program can be divided into up to 128 tasks. Using smaller task programs makes it easierto structure programs and contributes to shorter cycle times. Better Execution Performance for Interrupt Tasks (CJ2H CPU Unit with UnitVersion 1.1 or Later)With CJ2H CPU Units with unit version 1.1, overhead time for interrupt tasks is approximately 20%less than for unit version 1.0 even for normal usage. Also, by using High-speed interrupt function, itis possible to improve execution performance as shown below with certain restrictions.• Greatly reduce overhead time for interrupt tasks (interrupt task startup time + return time to cyclictasks).Example: For I/O interrupt tasks, the time for normal operation is 37 μs but the time is 25 μs ifHigh-speed interrupt function is used.• Minimum Interval Setting of 0.1 ms for Scheduled Interrupt Tasks(For unit version 1.0, the minimum interval is 0.2 ms.)1-4 CJ2 CPU Unit Software User’s Manual