Solution:
In order to
do this, you will have to apply a “Mask” to the value, which will null all the
bits in the integer value except the one that you want to keep.
For
example, If you wanted to isolate the third bit, you would have to apply a mask
that, in binary, will only have the third bit present. In Binary, this is the
number 4 (0100)
In order to
apply the mask, you must use the AND operator, which will leave a 1 if and only
if both the bits in that position are 1.
0110 1100 <= Data coming in
+
0000 0100 <= Mask
--------------------
0000 0100 <= Result
*note* the highlighted number is the data bit we wish to access
In decimal
notation, this would be expressed as 108 AND 4 = 4.
In order to
do this in an OPC Server, you would configure an alias to use the IF operator.
With the example above, where you wish to access the third bit in the integer,
the statement would appear as:
IF(INPUT
And 4 = 4, 1, 0)
Therefore,
if the bit in position 3 is a 1, since 1 AND 1 =1, the IF statement would be
true and would return a 1. If the bit in position is 0, 0 AND 1 = 0, the IF
statement would return a false value, which is a 0.
|