Allen-Bradley 1772-LSP

The Mini-PLC-2/05 processor is functionally similar to the Mini-PLC-2/15 processor. The Mini-PLC-2/05 processor has some additional features: 3K CMOS RAM memory 488 timers, up to 2944 word capacity data table (23 blocks), ladder diagram and functional block instruction set, four function arithmetic capabilities, remote mode selection, on-line programming, block transfer capability, 70 message storage, 198 message storage with the PLC-2 Family Report , data highway compatibility, selectable timed interrupts, and expanded math capability

When the processor detects a voltage at an input terminal, it records that information by turning the corresponding bit on. Likewise, when the processor detects no voltage at an input terminal, it records that information by turning the corresponding bit off. If, while executing your program, the CPU decides that a particular output terminal should be turned on or off, it records that decision by turning the corresponding bit on or off. In other words, each bit in the I/O image tables corresponds to the on or off status of an I/O terminal.

The processor controls the status of output devices or instructions in accordance with program logic. Every instruction in your program requires execution time. These times vary greatly depending upon the instruction, the amount of data to be operated on, and whether the instruction is true or false. There are two types of scans : 1. I/O scan (775ms without forcing: 1 ms with forcing) 2. Program scan (15ms/K of user memory)