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Synchronized
pre-heating
Eliminates differential heating during startup due to different
heat rates of individual heaters in applications such as extruders
and injection hot runner control. The setpoint ramp rates of all
heating zones within a group are synchronized by “holding back”
the ramping setpoint. In order to achieve this, the individual loop
band alarms are controlled by the common alarm output and isolated
logic input functions
PC interface
port + OPC based configuration software
The integrated configuration port uses special software and an adaptor
allowing:
- Easy configuration of the instrument, with descriptions
of the parameters and the relative limits.
- Computer storage of the complete configuration
allowing it to be copied to other RFS units.
- Copying and cloning of the configuration to a
new instrument.
- The configuration interface port can be used
for configuration and for monitoring the process during setup.
Smart
tuning
Automatically adjusts the PID parameters according to the process
dynamics. An important characteristic of the Eurotherm Controls
continuous self tuning algorithm is its ability to optimize control
parameters without injecting any artificial disturbances into the
system.
Sequential
addresses (Modbus) for commonly accessed parameters
To maximize the data transfer rates between the RFS and the host
supervisory system, important operating parameters are grouped.
Digital status information is transferred as data words to increase
efficiency. The RFS is able to communicate relevant parameter information
with a single data request, instead of a series of separate address
operations.
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Process
protection alarms
Process (high or low limit), Band and Deviation alarm outputs are
available with the additional flexibility of latching and masking
functions until the process variable reaches the alarm threshold.
Band and Deviation alarms are also masked after a setpoint change
until the process variable reaches the alarm threshold. The alarm
latching function holds the alarm on until it is acknowledged.
Startup
energy management
To reduce the maximum electrical loading at machine startup, the
sequence of the RFS control outputs is scheduled according to the
selected instrument Modbus address. This significantly reduces maximum
startup current requirements and offers potential savings in electrical
installation capacity and cabling specification requirements.
Communication
availability of I/O
All RFS I/O can be read directly over the Modbus communication interface
by the host supervisory system. Additionally, the communication
host can write to RFS outputs that are not assigned as alarm or
status functions. This expands available PLC and host supervisory
system I/O, simplifies machine troubleshooting and provides the
ability to perform remote diagnostics.
OFD -
output failure detection (optional)
Using the CT input, the output failure detection function
monitors the current in the load driven by output 1. Load and actuator
protection is provided in the following manner:
During the ON period of the output, the instrument measures
the current through the load and generates an alarm condition if
the current is lower than a pre-programmed threshold. A low current
indicates a partial or total breakdown of the load or actuator SSR.
During the OFF period of the output, the instrument measures
the leakage current through the load and generates an alarm condition
if the current is higher than a pre-programmed threshold value.
A high leakage current indicates a short circuit of the actuator.
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