Technical data

Appendix
27.3 Data Types and Parameter Types
Programming with STEP 7
610 Manual, 05/2010, A5E02789666-01
27.3.4.1 Format of the Parameter Types BLOCK, COUNTER, TIMER
STEP 7 stores the parameter types BLOCK, COUNTER, and TIMER as binary numbers in a word
(16 bits). The following figure shows the format of these parameter types.
The permitted number of blocks, timers, and counters is dependent on the type of your S7 CPU.
You will find more information on the permitted number of timers and counters and on the
maximum number of available blocks in the data sheets for your CPU in the "S7-300
Programmable Controller, Hardware and Installation Manual" or in the "S7-400, M7-400
Programmable Controllers, Hardware and Installation Manual."
27.3.4.2 Format of the Parameter Type POINTER
The following figure shows the type of data that is stored in each byte.
The parameter type POINTER stores the following information:
• DB number (or 0 if the data are not stored in a DB)
• Memory area in the CPU (the following table shows the hexadecimal codes of the memory
areas for the parameter type POINTER)
Hexadecimal Code Memory Area Description
b#16#81 I Input area
b#16#82 Q Output area
b#16#83 M Bit memory area
b#16#84 DB Data block
b#16#85 DI Instance data block
b#16#86 L Local data (L stack)
b#16#87 V Previous local data