Read / write
Read / write
Read / write
Read / write
SCR
S
NO
NO
7.2 Direct and indirect addressing
When you write the program, you can use the three ways to address instruction:
1. Direct addressing
2. Symbol addressing
3. indirect addressing
Direct addressing
PLC can directly specify the memory area, size, and location;
In order to read/write a bit in the memory area, you need to specify the address. The
address Includes memory area identifier, byte address, a period and number.
Example:
Specifying byte 、 word and double word addresses are similar to specifying bit
address.
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