BLN nobel G5, Техническое руководство

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G5 Weighing Instrument
1-1
1. Introduction
General
The G5 PM Indicator is a high performance single-channel weight indicator (PM model,
panel mounted) intended for industrial systems.
The basic function is to convert the signals from strain gauge transducers to useful
weight information. Transducer excitation is included as well as parameter controlled
signal processing, indication of output levels, error supervision and operation of
optional external equipment.
As long as the error supervision detects no error, a signal called ‘In process’ is then
present but if an error is detected, ‘In process’ will be off and a specific error
message will be displayed. ‘In process’ can be set to control any digital output. Note
that there are weighing channel specific and instrument specific error detection.
All functions in the G5 Instrument are controlled by set-up parameters. Setting of
parameter values can be done from the PM front panel. Maintenance functions can be
accessed locally or remotely.
It is possible to load new software into the instrument using a SD-Card.
The instrument has 4 level supervising functions and 4 set-point functions.
Power supply
The G5-PM (panel mount indicator) is available as 24 VDC model. All input and output
signals are galvanically isolated from the power supply.
Strain gauge input
Both excitation voltage and the output signal from the transducer are measured at the
transducer to avoid influence from voltage drop in the connection cable. Excitation to the
transducer, from the G5 Instrument is provided over separate wires.
A shielded 6-wire cable must be used to connect a distant transducer to the instrument.
The analog signals from the transducer are converted to digital form and filtered to give
an internal transducer signal with high resolution.
The transducer excitation and signal values are combined to form an internal
transducer signal, representing the load on the transducer. Influenced by calibration
data, this signal is converted to a digital measurement value, the weight value, which
can be presented at the local display window and at external equipment.
Communication
The instrument utilizes the serial interface, Ethernet and a fieldbus interface for
communication with control system or computer. The serial interface consists of a RS-
485/RS-422 connection that can be used with 2- or 4-wire connection.
Weight values, level status, error status etc. can be collected and commands given
through the communication interfaces. G5 Instruments can be controlled from a master
computer or PLC using the serial interface, Ethernet interface, field bus interface or
digital I/O.
Modbus RTU protocol is used for the serial interfaces, Modbus TCP and EtherNet/IP
for the Ethernet connection. Optional fieldbus interface for Profibus, DeviceNet or
ControlNet can be used.