Product Overview
SIWAREX FTA
3-8
3.5 Function
The primary task of the SIWAREX FTA consists of the precise measurement of the
current weight values in up to three measurement ranges and the exact control of
the weighing procedure. The control of the weighing procedure is completely run
from the weighing module as if in separately constructed weighing electronics. The
integration in SIMATIC enables the progress of the weighing procedure to be
influenced directly from the PLC program however. This enables reasonable task
distribution: The extremely fast weighing functions are performed in the SIWAREX
module, latching and signal linking is done in the PLC.
There are different automatic weighing procedures for which SIWAREX FTA can
be configured optimally by defining the corresponding parameters.
The following operating modes can be defined:
-
Non Automatic Weighing Instrument – conforming with OIML R-76
-
Automatic Gravimetric Filling Instrument – conforming with OIML R-61 (AWI)
-
Automatic catch weighing instrument – conforming with OIML R51 (AWI)
-
Automatic Totalising Filling Instrument- totalising – conforming with OIML R
107 (AWI)
During the weighing procedure, SIWAREX FTA monitors and controls a multitude
of signals. The optimised system internal data exchange enables a direct
evaluation of weighing signals and states in the PLC program.
The weighing procedure influence on the PLC enables a flexible adjustment to suit
the changes in the system technology.
SIWAREX FTA is already adjusted in-house. Therefore, the scale can be adjusted
to theoretical settings without using any adjustment weights and modules can be
exchanged without readjusting the scale. Exchanging modules during running
operation is also possible when working with “active bus modules”.
The SIWAREX FTA has two serial interfaces. An RS 485 interface is used for
connecting digital remote displays. A PC can be connected to the RS 232 interface
for setting SIWAREX FTA parameters.
The weighing module SIWAREX FTA can also be used in explosion hazard areas
(zones 21 and 22). Load cells are supplied with inherent safety with zone
1 applications using an optional Ex-interface SIWAREX IS.
If the regulation code OIML is set in the adjustment data, there will be a waiting
period of 60 seconds after rebooting the SIWAREX FTA before the weight value is
displayed. There is no waiting time when using digital load cells.
