Beckhoff ELX3312, Operating Manual

Page: 58 / 88

Parameterization and programming
ELX3312 and ELX3314 58 Version: 1.3.0
5.3.2 Siemens bits, index 0x80n0:05
If this bit (index 0x80n0:05 [ } 74] ) is set, status displays are shown for the lowest three bits. In the error case
overrange or underrange , bit 0 is set.
5.3.3 Undershoot and overshoot of the measuring range
(underrange, overrange)
U
k
> Uk
max
: Index 0x60n0:02 [
}
76] and index 0x60n0:07 [
}
76] (overrange and error bit) are set. The
linearization of the characteristic curve is continued with the coefficients of the overrange limit up to the limit
stop of the A/D converter or to the maximum value of 0x7FFF.
U
k
< Uk
max
: Index 0x60n0:01 [ } 76] and index 0x60n0:07 [ } 76] (underrange and error bit) are set. The
linearization of the characteristic curve is continued with the coefficients of the underrange limit up to the limit
stop of the A/D converter or to the minimum value of 0x8000.
For overrange or underrange the red error LED is switched on.
5.3.4 Notch filter (conversion times)
The ELX331x terminals are equipped with a digital filter. The filter performs a notch filter function and
determines the conversion time of the terminal. It is enabled via index
0x80n0:06 [
}
74] parameterized via
index 0x80n0:15 [
}
74] . The higher the filter frequency, the faster the conversion time.
Index 0x80n0:06
The filter function is always active even if the bit is not set, since this is obligatory for the measure-
ment process!
The filter characteristics are set via index 0x8000:15
The filter frequencies are set for all channels of the ELX331x terminals centrally via index 0x8000:15
[ } 74] (channel 1). The corresponding indices 0x8010:15 of the ELX3312 or 0x8010:15,
0x8020:15, 0x8030:15 of the ELX3314 have no parameterization function.
Conversion time
The conversion time is determined as follows:
No. of active channels * no. of measurements * no. of filter p computing time
= conversion time
Example for ELX3312 (2 channels)
3 measurements (thermocouple, wire breakage, cold junction), filter 50 Hz
2 channels * 3 measurements * (1/50 Hz) + 6 ms ≈ 126 ms
Example for ELX3314 (4 channels)
3 measurements (thermocouple, wire breakage, cold junction), filter 50 Hz
4 channels * 3 measurements * (1/50 Hz) + 12 ms ≈ 252 ms