Siemens SIWAREX FTC, Device Manual

Page: 47 / 149

W
EIGHING
F
UNCTIONS AND
P
ARAMETERS
Name Type Address Default Range of Values / Meaning Reference
Operating mode
BYTE DBB111 0 Operating mode:
0 NAWI filling procedure
1 NAWI emptying procedure
2 Force measurement
3 Belt scale
4 Loss-in-weight scale
5 Bulk flow measurement device
5.2.30
Reserve_3_110 BYTE DBB112 0 Reserved
Load cell type
BYTE DBB109 0 0: analog load cell
1: METTLER TOLEDO type WM or WMH
2...255 analog load cell 5.2.37
Timeout digital LC WORD DBW110 240 Timeout in ms for receiving the cyclic weight
value of the digital load cell
5.2.38
Regulations STRING
[4] DBB116 “----“ "OIML" : = Regulation code OIML
"----": = No regulation code 5.2.39
Weight unit
STRING
[4] DBB122 kg Weight unit 5.2.40
Weight unit large STRING
[4] DBB128 t Large weight unit 5.2.41
Length unit STRING
[2] DBD134 m Length units (belt scale only)
5.2.42
U Factor REAL DBD138 1000 Conversion factor weight unit > Large weight
unit 5.2.43
Determination time 3
TIME DBD140 10000 Adjustment or zero setting time for dynamic
zero setting, taring or adjusting 0... max. 900
000 ms (belt scale only) 5.2.44
144
Table 5-2 DR3 Allocation
5.2.1 DR3 - Adjustment Digits 0, 1, 2, 3, 4, for the Zero Point and Adjustment Weights 1,
2, 3, 4
The analog measurement value coming from the load cells is converted into a
digital value with an analog-digital converter. A weight value is then calculated from
this digital value. All functions of the SIWAREX FTC then uses this weight value for
executing their task.
To calculate the weight value from the digital value, the characteristic curve of the
measurement system must be determined. In the simplest case, the characteristic
curve is defined by points 0 and 1. The first operating point (point 0) is always
determined by the empty scale alone with its own construction weight. The weight
of its own construction, the scale load cells deliver a measurement voltage to the
SIWAREX FTC. After the analog-digital conversion of the measurement voltage,
the digital value (adjustment digit 0) is assigned the zero point (zero weight).
For determining the average value of the adjustment point for the belt scale (zero
point, adjustment weight) over a predefined period of time, the determination time
must be defined. This time entry is not applicable for other operating modes.
If the scale is loaded with a known calibration weight (e.g. with 50 % of the
measurement range), then the second operation point can be determined. The new
digital value from the analog-digital converter is now assigned the calibration weight.
The characteristic curve can be further adjusted using a maximum of three other
points that must lie above point 1.
SIWAREX FTC 5-35