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User Manual Chapter 10
GFK-1503F Jan 2020
Instruction Set Reference 103
10.1.3 Bit Operation Functions Exclusive OR
The Exclusive OR function compares each bit in bit string I1 with the corresponding bit in
string I2. If the bits are different, a 1 is placed in the corresponding position in the output bit
string.
Figure 62
I1 and the corresponding bit in string I2, beginning at the least significant bit in each. For
each two bits examined, if only one is 1, then a 1 is placed in the corresponding location in
bit string Q. The Exclusive OR function passes power flow to the right whenever power is
received.
If string I2 and output string Q begin at the same reference, a 1 placed in string I1 will cause
the corresponding bit in string I2 to alternate between 0 and 1, changing state with each
scan as long as power is received. Longer cycles can be programmed by pulsing the power
flow to the function at twice the desired rate of flashing; the power flow pulse should be one
scan long (one-shot type coil or self-resetting timer).
The Exclusive OR function is useful for quickly comparing two bit strings, or to blink a group
of bits at the rate of one ON state per two scans.
Parameters of the Exclusive OR Function
Input/ Output Choices Description
enable flow When the function is enabled, the operation is
performed.
I1 I, Q, M, T, S, G, R, AI,
AQ, constant Constant or reference for the first word to be XORed.
I2 I, Q, M, T, S, G, R, AI,
AQ, constant Constant or reference for the second word to be
XORed.
ok flow, none The OK output is energized whenever enable is
energized.
Q I, Q, M, T, SA, SB, SC
(not S), G, R, AI, AQ Output Q contains the result of the operation.