HEIDENHAIN TNC 407 (243 020) Technical Manual - Manual (Page 479)

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TNC 407/TNC 415/TNC 425 2 Program creation 01.98
2.2 Address allocation
2.2.1 Operand directory
Operand Abbreviation Address range
Marker M (Marker) 0 to 3023
Input I (Input) I0 to I31; I128 to I152;
I64 to I126 (first extension board);
I192 to I254 (second extension board)
Output O (Output) O0 to O30;
O32 to O62(first extension board);
O64 to O94 (second extension board);
Counter C (Counter) Set counter : C0 to C31
Counter contents: C48 to C79
Release count pulse: C96 to C127
Timer T (Timer) Timer start: T0 to T47
Timer running: T48 to T95
Byte B (Byte) 0 to 1023 (8 Bit)
Word W (Word) 0 to 1022 (16 Bit)
Doubleword D (Doubleword) 0 to 1020 (32 Bit)
Constant K - 2 147 483 647 to + 2 147 483 647
2.2.2 Addressing the memory
The memory for the Operands B (8 Bit), W (16 Bit), D (32 Bit) is only 8 Bit wide. Since the Operands
can be 8,16 or 32 Bit wide, an overlap of the memory areas will occur, which must be taken into
account in addressing the memory.
8 bit
0 7 B0
B1023
B1022
B1021
B1020 D1020 W1020
B1
B2
B3
B4
B5
W0 D0
W2
W4 D4
W1022
..
.
..
.
..
.
..
.
➞ High-Byte for W; Highest-Byte for D
➞ Lowest-Byte for D
➞ Low-Byte for W
In Byte addressing every address from 0 to 1023 is accessible. In Word addressing, every second
address from 0 to 1022 is accessible and in Doubleword addressing every fourth from 0 to 1020.
The address parameter gives the High Byte for a Word Address (W) , or the Highest Byte for a
Doubleword address (D).