The DigiRail line of smart transmitters with Modbus RTU communication interface provide a simple way for integrating analog or digital signal to supervisory systems. Featuring up to two universal input analog signal channels they are the most econmical way to deliver analog input to PLC's and SCADA systems.

The input signal are isolated from power thus protecting the electrical instruments by eliminating ground loop effects. This reduces substantially the undesirable interferences and instabilities in sensor measurements

DigiRail can be easily configured and calibrated via the digital interface by using the Windows based DigiConfig software.

Models

The DigiRail line of transmitters includes 3 models, based on their input or output types:

• DigiRail-1A and DigiRail-2A, with 1 or 2 universal analog inputs respectively
• DigiRail-4C, with 4 digital counters
• DigiRail-2R, with 2 timer relay outputs

Configuration

DigiRail Configuration is done via the RS485 interface by using Modbus RTU commands.

The DigiConfig software allows for configuration of all DigiRail features as well as complete calibration and diagnosis. It automatically detects active devices in the Modbus network and permits configuration of all parameters.

Specifications

• Analog inputs: programmable for thermocouples (J, K, T, E, N, R, S, B), Pt100, mV, V, mA. Refer to table 1.
• Cold junction compensation for thermocouples and compensation for Pt100 3-wire cables.
• Open loop detection for thermocouples, Pt100 and mV.
• Sampling rate for 1 analog input: 10Hz for mV, V and mA. 5Hz for T thermocouples and Pt100.
• Analog input resolution: 17 bits.
• Digital inputs: in voltage, 4 to 35V to activate internally limited current in 5 mA
• Digital outputs: 8A / 250 Vac SPDT relay, resistive load.
• Power: 10 to 35 Vdc, 50mA maximum current.
• 2-wire RS485 communication with Modbus RTU protocol. Configurable address and baud rate (1,200 to 115,200bps).
• LED indicators for communication and status. Key for resetting communication parameters to original factory default.
• Accuracy (at 25°C): Pt100, mV, V and mA: ±0.15% of full scale. Thermocouples: ±0.25% of full scale.
• Temperature effect: 0.003% of full scale/°
• Cold junction compensation for thermocouples: ±1°C at 25°C. ±0.05 °C/°C
• Isolation: 1000 Vac from inputs (analog or digital) and power or communication. Communication and power are not isolated from one another nor are the analog inputs from each other. Every two digital inputs are isolated from other pairs of same inputs.
• Windows.based configurator software.
• Dimensions: 72 x 78 x 19mm.
• Mounting: 35mm DIN rail. Refer to drawing.
• Working temperature: 0 to 70°C

Electrical Connections

Block Diagrams

Input Types and Maximum Ranges

Dimensions