Novus DigiRail-VA User manual

NOVUS AUTOMATION 1/17
DigiRail-VA
USER GUIDE −V1.0x G
1. MAIN FEATURES ......................................................................................................................................................... 2
2. SPECIFICATIONS ........................................................................................................................................................ 3
3. INSTALLATION AND OPERATION ................................................................................................................................... 4
3.1 MECHANICAL INSTALLATION .................................................................................................................................. 4
3.1.1 DIMENSIONS ................................................................................................................................................ 4
3.2 ELECTRICAL INSTALLATIONS AND OPERATION ........................................................................................................ 4
3.2.1 INSTALLATION RECOMMENDATIONS ............................................................................................................... 5
3.2.2 POWER SUPPLY............................................................................................................................................ 5
3.2.3 RS485 .......................................................................................................................................................... 5
3.2.4 USB INTERFACE............................................................................................................................................ 5
3.2.5 AC INPUTS ................................................................................................................................................... 6
3.2.6 4-20 MA OUTPUT ........................................................................................................................................... 8
3.2.7 0-10 V OUTPUT.............................................................................................................................................. 8
4. INDICATOR LIGHTS (LEDS) ......................................................................................................................................... 10
5. USB DRIVER INSTALLATION ....................................................................................................................................... 11
5.1 WINDOWS 11 ...................................................................................................................................................... 11
6. HOW TO SET AND SELECT A SERIAL PORT (COM) − WINDOWS ...................................................................................... 13
7. CONFIGURATION SOFTWARE..................................................................................................................................... 14
7.1 INITIAL CONFIGURATION AND SOFTWARE INSTALLATION........................................................................................ 14
7.2 EQUIPMENT FIRMWARE UPDATE .......................................................................................................................... 14
8. MODBUS COMMANDS AND REGISTERS TABLE............................................................................................................. 15
8.1 SUPPORTED MODBUS COMMANDS ....................................................................................................................... 15
8.1.1 READ HOLDING REGISTERS – 03H ................................................................................................................ 15
8.1.2 WRITE SINGLE REGISTER – 06H.................................................................................................................... 15
8.1.3 WRITE MULTIPLE REGISTERS – 16H .............................................................................................................. 15
8.2 HOLDING REGISTERS TABLE ................................................................................................................................ 15
8.3 DETAILS ABOUT SOME REGISTERS....................................................................................................................... 16
8.3.1 REGISTERS 20 TO 28 – MEASUREMENT VALUE IN INTEGER FORMAT................................................................ 16
8.3.2 REGISTERS 200 AND 201 – SERIAL NUMBER................................................................................................... 16
8.3.3 REGISTER 202 – FIRMWARE VERSION ........................................................................................................... 16
8.4 FLOATING POINT FORMAT.................................................................................................................................... 16
9. WARRANTY .............................................................................................................................................................. 17

DigiRail-VA
NOVUS AUTOAMTION 2/17
1. MAIN FEATURES
DigiRail-VA is a transmitter and signal conditioner related to alternating current (single-phase), capable of measuring the following quantities on the
True-RMS:
•Voltage
•Current
•Active, reactive, and apparent power
•Frequency
•Power Factor
The measured values can be read out via the RS485/Modbus RTU interface. In addition, they can be retransmitted simultaneously via the 4-20 mA
and 0-10 V outputs.
These features make DigiRail-VA an excellent solution for measuring consumption profiles in machines and single-phase installations.
This equipment is not intended for commercial measurement of electrical energy!

DigiRail-VA
NOVUS AUTOAMTION 3/17
2. SPECIFICATIONS
Power Supply: 10 to 40 Vdc. Max consumption: approx. 40 mA @ 24 V; plus 20 mA when you used a 4-20 mA output. Peaks of up to 20 mA can
also occur when the equipment is sending data through the RS485 interface.
Operation Temperature: 0 to 60 °C.
Dimensions:99.5 x 114.0 x 17.5 mm.
Weight:96 g.
Enclosure: PA66, with metallic attachment for 35 mm DIN track.
Internal protection against polarity inversion of the power supply voltage.
Wire gauge: AWG 28 to 12.
Recommended torque: 4 kgf·cm.
Voltage input range: 0 to 300 Vac (RMS).
Current input range: 0 to 5 Aac (RMS).
Frequency input range:between 45 to 65 Hz.
Analog outputs: 4-20 mA and 0-10 V.
Analog output rangeability:10:1. A bigger zoom is allowed, but with accuracy loss.
RS485 Serial Interface: Modbus RTU Protocol – 3 wires.
The inputs are isolated from the outputs and communication interfaces. Isolation: 2500 Vac / 1 minute.
Accuracy:
•Reading by RS485:
oRMS voltage, RMS current, active power (real), apparent power and reactive power: 0.25 % (True-RMS).
oPower factor and frequency: 0.5 %.
•Reading by the 4-20 mA output:
oRMS voltage, RMS current, active power (real), apparent power and reactive power: 0.5 % (True-RMS).
oPower factor and frequency: 1.0 %.
•Reading by the 0-10 V output:
oRMS voltage, RMS current, active power (real), apparent power and reactive power: 0.5 % (True-RMS).
oPower factor and frequency: 1.0 %.

DigiRail-VA
NOVUS AUTOAMTION 4/17
3. INSTALLATION AND OPERATION
3.1 MECHANICAL INSTALLATION
The DigiRail-VA housing was designed for installation on DIN rail 35 mm.
For installation on the rail, you should locate the clamp at the base and press it against the track.
3.1.1 DIMENSIONS
Figure 1 –Dimensions
3.2 ELECTRICAL INSTALLATIONS AND OPERATION
DigiRail-VA has connectors for the power supply, for the inputs for AC measurement, for the output for analog transmission and for the RS485
serial communication interface. Furthermore, it has a USB mini-B interface.
Figure 2 –Connection terminals
Figure 03 illustrates the electrical connection terminals. Terminals 4, 5 and 6 connect to the RS485/Modbus interface. Terminals 7, 8 and 9 are
intended for the analog outputs of the device (4-20 mA and 0-10 V – they share the same "negative" terminal). Terminals 10, 11 and 12 are used to
power the DigiRail-VA (terminals 10 and 11 are interconnected internally).
Terminals 1, 2 and 3 are used for AC measurements and must be connected carefully. Refer to AC INPUTS section for connection details.
Figure 3 –Electrical connections

DigiRail-VA
NOVUS AUTOAMTION 5/17
3.2.1 INSTALLATION RECOMMENDATIONS
We recommend using an appropriate fuse for the protection of the load to be measured.
•Input conductors should travel the system plant separately from the output and supply conductors, in grounded electrical ducts.
•The power source of the instruments should come from a network that is appropriate for the instrumentation.
•The use of RC FILTERS (47 Ωand 100 nF, in series) parallel to the contactor coils and solenoids that are near or connected to the equipment
is recommended.
•In control applications, it is essential to consider what can happen when any part of the system fails.
•Section of used wires: minimum gauge of 0,14 mm².
3.2.2 POWER SUPPLY
The terminals 11 and 12 (or 10 and 12) are intended for the power supply for DigiRail-VA. The polarity of the power supply must be carefully
observed and the voltage level.
3.2.3 RS485
The RS485 interface of DigiRail-VA has terminals for 3-wire communication (including the common) and operates as a Modbus RTU slave. The
commands and the table of available registers can be viewed in the MODBUS COMMANDS AND REGISTER TABLE.
This interface can be configured to operate in the following baud rate: 1200, 2400, 4800, 9600, 19200, 38400, 57600, and 115200. In addition, it
can be configured to operate with one or two stop bits, and parity even, odd or none.
D1 D D+ B Bidirectional data line. Terminal 4
D0 D- A Inverted bidirectional data line. Terminal 5
C
Optional connection that improves the communication
performance. Terminal 6
GND
Table 1 –RS485 connections
Figure 4 –RS485 connections
3.2.4 USB INTERFACE
DigiRail-VA has a USB device interface, used for configuration and monitoring. The Windows operating system will detect the device as a virtual
serial port, allowing the use for supervisory software (SCADA).
To access this interface should be use the USB cable supplied with the equipment. When you first access, you need to install the USB drivers on
the computer. To see how to do this, see USB DRIVER INSTALLATION section.
The communication of this interface is by the Modbus RTU protocol. The commands and the table of available registers of this interface can be
viewed in the MODBUS COMMANDS AND REGISTERS TABLE.
Note: This equipment cannot be powered from its USB interface. An external power supply must be used for configuration.

DigiRail-VA
NOVUS AUTOAMTION 6/17
3.2.5 AC INPUTS
The measurement circuit is electrically isolated from the rest of the equipment (power circuits and interfaces). However, great care must be taken
with electrical wiring connections. Take care to comply with the maximum voltage and current set (see SPECIFICATIONS chapter).
To measure higher voltages or current levels to be measured, you should use current or voltage transformers (see USING CURRENT
TRANSFORMERS AND VOLTAGE TRANSFORMERS section).
TERMINAL 1 2 3
SIGN COMMOM I V
Table 2 –Terminals
The current measurement is done by an internal shunt resistor, so that the DigiRail-VA is connected in series with the load to be measured. The
following figure illustrates the device connected to the measuring circuit.
Figure 5 –Measurement of voltage and current
Despite being common simultaneous measurement of voltage and current, you can connect just the part on the voltage or current for
measurement. In such cases, the measurement of the variable not connected will present value near zero as the calculated values of the side
variables (power and power factor). The figures below illustrate the connections in these cases.
Figure 6 –Solely measurement of voltage
Figure 7 –Solely measurement of current

DigiRail-VA
NOVUS AUTOAMTION 7/17
USING CURRENT TRANSFORMERS AND VOLTAGE TRANSFORMERS
To expand the capacity of measuring levels of current or voltage DigiRail-VA, you can use voltage and/or current transformers.
Figure 8 –Connecting with current transformer
Figure 9 –Connection with voltage transformer
Figure 10 –Connection with current and voltage transformers.
In any of the cases, the maximum limits of the equipment must be respected, that is, the use of a current transformer requires that it has a
maximum output of 5 A and the use of a voltage transformer requires it to have an output maximum of 300 V.
Phase inversion can generate a considerable error on some measurements. To avoid that, some care must be taken when using current or voltage
transformers so their polarity should keep the signal with its same original phase.
The transformer ratio should be informed in DigiRail-VA settings so you can make the correction of the measured value, adjusting to reality.
Similarly, if the use of a transformer produces a phase shift between current and voltage in the secondary, can be corrected through the option
"Allow the Correction of Phase" in the "Diagnostics" tab for DigiConfig.
Example 1: Using a voltage transformer with 1000 V input and 300 V output.
In this case, you must inform on DigiConfig that be used a voltage transformer, selecting the appropriate box. You must then inform the
transformation ratio (in = 1000 V, out = 300 V).
Example 2: Using a current transformer with 50 A input and 4 A output.
In this case, you must inform on DigiConfig that be used a current transformer, selecting the appropriate box. You must then inform the
transformation ratio. As the input range is 0 to 5 A, and in this example the current transformer to be used does not match the specification,
adjust the parameter of the input current of the current transformer, so that the ratio transformation is maintained.
50 / 4 = 12.5
12.5 x 5 = 62.5 → Input = 62,5 A
MEASUREMENT OF FREQUENCY AND POWER FACTOR
The frequency measurement is performed by the voltage input. In case the voltage value is close to zero, the frequency calculation may be
inaccurate and wrong values may happen. That is why DigiRail-VA inhibits the frequency measurement when voltage is near zero, typically below
0.5% of full scale. The inhibition of the frequency measurement, indicated as "0 Hz", also happens when it is not performing the voltage
measurement, as in the case shown in Figure 06.
Measurement of power factor there need voltage and current being measured by DigiRail-VA, it is a calculated value based on the phase shift of
these two quantities. If one of the values of the voltage or current is near zero, the calculated value of power factor may result in wrong values. That
is why the DigiRail-VA inhibits power factor measurement when the voltage or current showing small values, typically 0.1 % of full scale. This

DigiRail-VA
NOVUS AUTOAMTION 8/17
inhibition of measuring power factor, denoted as "0", also happens when it is not performing the measurement of voltage or current, as in the cases
illustrated in Figures 06 or 05.
3.2.6 4-20 mA OUTPUT
The 4-20 mA output can be used to transmit any of the measures in the AC input:
•RMS Voltage
•RMS Current
•Active Power
•Apparent Power
•Reactive Power
•Power Factor
•Frequency
This output can be disabled if necessary.
Transmission is based on the full scale of the desired variable (e.g., 0 to 300 V for the rms voltage) or based on a reduced scale (e.g. transmit a
value of rms voltage on the range from 80 to 140 V, where 80 V corresponds to 4 mA and 140 V to 20 mA).
Finally, you can select the behavior of the 4-20 mA output in case of error: current lower than 4 mA or higher than 20 mA.
Figure 11 –Connecting the 4-20 mA loop output
The 4-20 mA output is NOT isolated from the 0-10 V output, as they are interconnected through the “negative”
pole. In addition, this conductor is also connected to the negative of the power source!
Therefore, you should be careful when using the 4-20 mA and 0-10 V outputs to send signals to other devices that
are powered from the same source as DigiRail-VA.
If the 4-20 mA and 0-10 V outputs are used at the same time, you can have problems if both are read by the same
device and if the device does not have isolated inputs.
3.2.7 0-10 V OUTPUT
The 0-10 V output can be used to transmit any of the measures in the AC input:
•RMS Voltage
•RMS Current
•Active Power
•Apparent Power
•Reactive Power
•Power Factor
•Frequency
This output can be disabled if necessary.
The transmission is based on the full scale of the desired variable (e.g., 0-5 A for the rms current) or based on a reduced scale (e.g., transmit a
current effective value of range of 0.5 to 3 A, where 0.5 A corresponds to 0 V and 3 A corresponds to 10 V).
Finally, you can select the behavior of the output 0-10 V on error: Voltage equal to 0 V or exceeding 10 V.
Figure 12 –Connecting the 0-10 V output

DigiRail-VA
NOVUS AUTOAMTION 9/17
The 4-20 mA output is NOT isolated from the 0-10 V output, as they are interconnected through the “negative”
pole. In addition, this conductor is also connected to the negative of the power source!
Therefore, you should be careful when using the 4-20 mA and 0-10 V outputs to send signals to other devices that
are powered from the same source as DigiRail-VA.
If the 4-20 mA and 0-10 V outputs are used at the same time, you can have problems if both are read by the same
device and if the device does not have isolated inputs.

DigiRail-VA
NOVUS AUTOAMTION 10/17
4. INDICATOR LIGHTS (LEDS)
Status LED:
It indicates the operational status of the equipment, according to the table shown below:
LED STATUS
MEANING
ON The input measurement is OK.
1 blink every 2 seconds Voltage input value greater than the range operation.
2 blinks every 2 seconds Voltage input value lower than the range operation.
3 blinks every 2 seconds
Current input value greater than the range operation.
4 blinks every 2 seconds
Current input value lower than the range operation.
5 blinks every 2 seconds Input frequency out of operating range.
OFF Possible hardware issues.
Table 3 –Status LED
Communication LED:
It indicates that an RS485/Modbus communication is in progress. Blinks whenever the DigiRail-VA is sending a Modbus frame via the RS485
interface (in response to a command).