Outputs (Nominal Value)
Analogue output nominal point requires a value representing the percentage of the analogue range up to 200%.
e.g. to set the nominal point of a 20mA output to 10mA, set the offset to 50 (50% of 20mA)
N.B. The upper and lower nominal points on bipolar outputs are symmetrical about the zero offset point.
e.g. setting the nominal point to 80% and the zero offset to 60% for a bipolar output (-20/0/+20mA) results in a
+8/+12/+16mA output corresponding to an input of +/-100%.
The range 0-100% corresponds to a frequency of 40-60Hz.
To set the centre frequency and the span use the following formula -
float Range, ZeroOffset;
Range = 2000/([Required Span in Hz]*2); // span * 2
ZeroOffset = (([Centre Frequency] [Required Span in Hz] - 40)/5) * (-0.25* Range);
Nominal = Range + ZeroOffset
A programmer will use values corresponding to a CENTRE frequency and a span value in hertz.
The span will be interpreted as a range above and below the center frequency.
Accuracy will be compromised if the full span of 20Hz is reduced.
The centre frequency will always be NOMINAL * 0.5 if the above formula is used.
For the M560 transducers, the write functions require the General Pass Code to be valid.