Echelon Neuron - Manual (Page 87)

Neuron Tools Errors Guide 79
NCC# Description
248 Comparison is ineffective - result of comparison is a constant [NCC#248]
A conditional expression (comparison) which involves a constant value that
is out of the range of a variable value is an ineffective comparison; one that
always resolves to either the constant TRUE or the constant FALSE. The
Neuron C compiler detects such a condition and issues a warning assuming
that the comparison might be erroneous. This situation most commonly
occurs when an unsigned short is compared with a negative number, or a
short is compared with a constant that is a long. Recall that Neuron C
defines short to be 8 bits and long to be 16 bits.
void f(void) {
int i;
if (i < 300) {
// The comparison shown above is an
// ineffective comparison, since 'i'
// can only be in the range -128..127.
// The constant 300 is a long. This
// is most likely a programming error.
}
}
249
250 Loop, branch, or ‘when’ condition is always TRUE [NCC#249]
Loop, branch, or ‘when’ condition is always FALSE [NCC#250
The Neuron C compiler detects when some conditions are always FALSE or
always TRUE. This warning is generated to help programmers ensure that
their program is correct. A condition that is always FALSE, or TRUE, may
result from an erroneous conditional expression.