JUMO LOGOSCREEN 500, Руководство по эксплуатации, Страница: 21 / 100

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2 Instrument description
The following variables are used for the formulae:
- analog inputs (AE1 — AE6)
- counter/integrator channels (ZI1 — ZI6)
- logic inputs (BE1 — BE4)
- alarms
- errors
- Modbus-Flag (signal via serial interface)
- instrument-specific data (only after consultation with the manufacturer)
If counter/integrator values are used for calculation, please note the reduction
in accuracy, since, in this case, two different data formats have to be used for
calculation. The counters/integrators are calculated in the double-float format,
whereas the math module employs the single-float format to the IEEE 754
standard. Nevertheless, these values can still be integrated into the math
module.
Available as fixed functions are:
- difference
- ratio
- humidity
- moving average
For the moving average, it is necessary to enter the reference channel (in most
cases, the analog input no.) and the time (in minutes), which are used for cal-
culating the moving average.
The following operators and functions are available for the formulae:
+, -, *, /, (, ), SQRT(), MIN(), MAX(), SIN(), COS(), TAN(), **, EXP(),
ABS(), INT(), FRC(), LOG(), LN().
On going above or falling below the scaleable values, the math channel is
treated as for “out-of-range".
The formulae are entered in the PC, in the setup program. The mathematical
formulae cannot be edited on the instrument by using the keys.
H
Additional information can be found in
Chapter 5.4 “Math and logic module”
The channel number of a math channel indicates which
analog input is being used by the math channel.