Software 4.1.1.2 Minimum cycle time The time it takes to complete a PLC cycle is shortest if the PLC just processes the program. Calculating the cycle time Ш Sum total of execution times of module call commands Ш Sum total of command execution times (see table Set of Commands) Ш Process image update: 25 µs However, due to the possibility of using conditional module calls and conditional jump commands (JPC...), the cycle ti- me also depends on the internal and external states used as conditions. This gives the programmer the chance to optimise the pro- gram runtime by cleverly arranging his program.
A clear project structure ensures that the PLC is only enga- ged in operations that are relevant to the control process at that time. Another benefit ensues from storing the most frequently used bit operands in the on-chip RAM, because accesses to this memory are twice as fast as accesses to other types of memory ( а 3.10.5). 38