1804 HEIDENHAIN Technical Manual iTNC 530 HSCI
9.8.48 EQUAL TO [ ] (==[ ])
Syntax: ==[ ] (EQUAL[ ])
Operands: None
Action:
By using parentheses you can change the sequence of processing 
comparative commands in a statement list. The opening-parenthesis 
command puts the content of the word accumulator onto the program stack. 
This clears the accumulator for calculation of intermediate results.
The closing-parenthesis command gates the buffered value from the program 
stack with the content of the word accumulator. The iTNC saves the result in 
the accumulator again. Maximum nesting depth: 16 parentheses.
Comparative commands cause a direct transition from word to logical 
processing. If the specified comparative condition is true, the iTNC sets the 
logic accumulator to 1; if the condition is not fulfilled, it sets it to 0.
Example:
Multiply a constant with double word D36, compare the result with double 
word D12, and assign the result to output O15. 
Initial state: 
Constant = 1000 (dec) 
Double word  D12  = 15000 (dec) 
Double word  D36  = 10 (dec) 
Output O15 = ?
Function STL Accumulator 
content
Operand content
Load the double word 
D12 into the word 
accumulator.
L D12 15000 15000
Opening parenthesis: 
Buffer the accumulator 
content onto the program 
stack.
== [
Load the constant into the 
word accumulator.
L K1000 1000
Multiply the content of 
the word accumulator 
with double word D36.
x D36 10000 10
Closing parenthesis: Gate 
the accumulator content 
with the program stack 
(==[, >=[ ...); if condition 
not fulfilled, set logic 
accumulator to 0.
]
Assign the result to 
output O15.
= O15 0 0