Modulo gives unexpected result

[Controls Guy]

I have

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MATH V0 "TICKus() % 5"
and I got 65535 and 65532 in V0, which is written nowhere else in logic and there's no HMI.    How can a modulo operation return a value less than zero (if it's actually thinking -1 or -4), or a value greater than the divisor??

[franji1]

Modulo with negative numbers gives strange results (negative remainder).

Best to convert it to positive, although not sure what happens when it's -2147483648

ABS(TICKus()) % 5

[franji1]

However, realize that TICKus() will go from +2147483647 (0x7FFFFFFF) to -2147483648 (0x80000000) in 1 microsecond

[Controls Guy]

Ah, even though 32-bit I was assuming unsigned, not sure why.   

[Controls Guy]

Just generating a random.    ABS() would work or I can just use (TICKus() & 0x8FFF)%5.

Any better thoughts on an RNG?

[ADC Product Engineer]

Why not use RANDINT() or RANDREAL()?

[Controls Guy]

Cause of not knowing about them?