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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. |
