Tuesday, May 18, 2010

Mini PLC Memory Addressing

Mini PLC Memory Addressing

This addressing reference will help you to specify the address in memory of mini PLC-2 family of processors. For each PLC-2 processors it can alter the factory configuration of memory. For each PLC-2 processor, each word of memory has the PLC data type of unsigned word. Below is the table that shows memory maps of PLC-2/30.




Notes for above table:-

1. If not configured for output image table can be used for storage or timer/counter accumulated values.
2. Bits in this word are used by the processor for battery low condition, message generation and data highway.
3. If not configured for input image table, can be used for storage or timer/counter preset values.
4. In remote I/O system, bits in words 125 and 126 indicate remote I/O rack status. Or indicate that the size of this section is adjustable.

All data in PLC-2 memory is stored in 16-bit words. You address this data by word number and (optionally) bit number. You must express word and bit numbers in octal form. The general format for data table addresses as below:-




The general format for I/O image table addresses as below:-




The format of structure of timer accumulated value word as below:-



The format of structure of timer preset value word as below:-

No comments:

Post a Comment