RFS DIN Rail Temperature Controller

Designed to offer outstanding control performance and provide a comprehensive solution for a wide variety of applications; such as food processing, plastic manufacturing, and process applications requiring heat/cool control and process protection alarms in a compact DIN rail mounted package.

Universal thermocouple or RTD input coupled with a responsive SMART auto-tuning PID control algorithm that is equipped with special functions, including soft start and nonlinear cooling. A complete set of process protection alarm functions; high and low limit, band and deviation are included.

Modular interconnection allows simultaneous connection of all common instrument elements: power supply, serial interface, logic input and open collector output for common alarms. The RFS-AL alarm-logic input expansion unit makes use of the modular interconnection function to provide additional I/O capacity.

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:

1. Easy configuration of the instrument, with descriptions of the parameters and the relative limits.
2. Computer storage of the complete configuration allowing it to be copied to other RFS units.
3. Copying and cloning of the configuration to a new instrument.
4. 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.

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.

Case:

PC/ABS grey

Self-extinguishing degree:

V0 according to UL 746C

Front protection:

IP20

Dimensions:

131 x 117 x 22.5mm

Weight:

250g max.

Power supply:

switching 24VAC/VDC (±10% of nominal value)

Power consumption:

6VA

Insulation:

reinforced insulation is guaranteed between supply input, instrument inputs and outputs

Common mode rejection:

120dB @ 50/60Hz

Normal mode rejection:

60dB @ 50/60Hz

All inputs are configurable and calibrated at the factory.

RTD Input

• Type:3-wire Pt100
• Calibration:  according to DIN 43760
• Measuring current:  130µA
• Line resistance:  auto-compensation up to 20 ohms per wire with no measurable error
• Engineering units:  programmable ºC or ºF
• Sensor break: indicates break of sensor or one or more wires; indicates short circuit when sensor resistance <12 ohms

RTD  Pt100 3-wire

°C  -200.0/400.0  -200/800

°F  -200.0/400.0 -330/1470

Linear Inputs

• Scaling: programmable from keyboard -2000 to 4000
• Decimal point: programmable to any position

Input 

0-20 mA 4-20 mA 0-60 mV 12-60 mV

Impedance 

<5 ohms <5 ohms >1M ohms >1M ohms

Output 1 and 2 – SSR

Function:

control output

Type:  non-isolated Logic level 1:

• 27VDC max. @ 1mA
• 14VDC min. @ 20mA

Logic level 0:

< 0.5V

Relay Type

• Output 1  Function: control output
• Type: SPST
• Contact load: 3A @ 250VAC max. on resistive load
• Output 2 Function: control output or alarm
• Type: relay with SPST contact
• Contact load: 3A @ 250VAC max. on resistive load
• Output 3 Function: alarm output
• Type: relay with SPDT contact
• Contact load: 3A @ 250VAC max. on resistive load
• Output 4 Function: group alarm (common output)
• Type: open collector
• Contact load: 20mA max. @ 48V

Control Action

• Type: one (heating) or two (heating/cooling) control outputs
• Output action: time proportioning
• Control action: ON/OFF PI or PID + SMART
• Proportional band: 1.0% to 100.0% of the input range for one control element;
• 1.5% to 100.0% of the input range for two control elements;
• Setting PB = 0 causes ON/OFF control

Hysteresis:

programmable from 0.1% to 10.0% of the input span

Integral time:

programmable from 1 second to 20 minutes (or none)

Derivative time:

programmable from 1 second to 10 minutes (or none)