Lumel N20PLUS User Manual

DIGITAL PANEL METER

N20PLUS

USER’S MANUAL

1

2

Contents

1. APPLICATION AND METER DESIGN ........................................ 5

2. METER SET ................................................................................. 6

3. BASIC REQUIREMENTS, OPERATIONAL SAFETY ................. 6

4. INSTALLATION ........................................................................... 8

5. SERVICE.................................................................................... 10

6. MODBUS REGISTER MAP ....................................................... 18

7. ERROR CODES ........................................................................ 22

8. TECHNICAL DATA .................................................................... 23

9. EXECUTION CODES ................................................................ 26

3

4

1. APPLICATION AND METER DESIGN

The N20PLUS meter is a digital programmable panel instrument
destined for measurements of d.c. voltages or d.c. currents: unipolar or
bipolar, temperature through thermocouples (J, K) and Pt100 resistance
thermometers.

The N20PLUS meter has a built-in RS-485 interface and the MODBUS

RTU protocol provided on it, by means of which it is possible to congure

the meter or read measured values from it. The free eCon software

(available at www.lumel.com.pl) is destined for the conguration of the

N20PLUS meter. The meter should be connected to a PC computer via
the RS485 to USB converter, e.g. PD10.

Following parameters can be reprogrammed:
– display colour, individually in three intervals,

– thresholds of displayed overows

– display precision of the result (decimal point),
– highlight of the unit,
– automatic or manual compensation: temperature of ends in

measurements with thermocouples, or wire resistance in Pt100

measurements,
– averaging time of the measurement,
– recalculation of indications (individual characteristic),
– working modes for two outputs of OC type, to choose from 6 work modes;
– RS-485 transmission parameters;
– MODBUS bus settings.

The meter is equipped with two OC type outputs. The output
switching on is signaled by the highlight of the triangular alarm index
situated at the left display side, for the suitable alarm digit. The highlight
colour is always different from the colour of the displayed (measured)
value.
The meter has a galvanic separation between the supply, measuring
inputs and RS485 interface.

5

The protection grade of the meter from the front side is IP65. Dimensions
96 x 48 x 64 mm (including terminals). The meter housing is made of
self-extinguishing plastic.

Fig. 1. view of the N20PLUS meter

2. METER SET

The set is composed of:

- N20PLUS meter ........................................ 1 pc

- user’s manual ............................................ 1 pc

- clamps to  x in the panel ......................... 4 pcs

3. BASIC REQUIREMENTS
AND OPERATIONAL SAFETY

Symbols located in this service manual mean:

WARNING!

Warning of potential, hazardous situations. Especially
important, one must acquaint with this before connecting
the meter. The non-observance of notices marked by these
symbols can occasion severe injuries of the personnel and
the damage of the meter.

CAUTION!

Designates a general useful note. If you observe it, handling
of the meter is made easier. One must take note of this,
when the meter is working inconsistently to the expectations.

Possible consequences if disregarded!

6

In the safety service scope, the N20PLUS meter meets the
requirements of the EN 61010-1 standard.

Observations concerning the operational safety:

▪ All operations concerning transport, installation, and commissioning
as well as maintenance, must be carried out by qualied, skilled

personnel, and national regulations for the prevention of accidents
must be observed.

▪ Before switching the meter on, one must check the correctness of
connection to the network.

▪ The removal of the meter housing during the guarantee contract
period may cause its cancellation.

▪ The meter is destined to be installed and used in industrial
electromagnetic environment conditions.

▪ One must remember that in the building installation, a switch or a
circuit-breaker should be installed. This switch should be located
near the device, easy accessible by the operator, and suitably
marked.

7

4. INSTALLATION

The meter has separable strips with screw terminals which enable the con­nection of external wires of 2.5 mm2. In the version for current measure-

ment, the plug enables permanent  xing to the socket by means of screws.

One must prepare a hole of 92
thickness should not exceed 6 mm. The meter must be introduced from
the panel front with disconnected supply voltage. Before the insertion into

the panel, one must check the correct placement of the seal. After the
meter insertion into the hole,  x the meter by means of the clamps ( g. 2.).

+0.6

Fig. 2. Meter  xing.

 45

+0.6

mm in the panel which the

Fig. 3. Meter overall dimensions

8

4.1. Connection Diagrams

Rys. 3. Gabaryty miernika

4.1. Schematy podłączeń

~

Rys. 3. Gabaryty miernika

Rys. 4. Połączenia elektryczne miernika N20

PLUS

1 2 3

24V GND

24V

GNDA AL2 AL1 GND

RS485

B A zasilanie

~

PLUS

~

Rys. 3. Gabaryty miernika

Rys. 4. Połączenia elektryczne miernika N20

PLUS

1 2 3

Rezystor termometryczny w

układzie dwuprzewodowym z

kompensacją ręczną

1 2 3

Rezystor termometryczny w
układzie trójprzewodowym z
kompensacją automa tyczną

1 2 3

+ -

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

24V GND

24V

GNDA AL2 AL1 GND

RS485

B A zasilanie

Sygnały pomiarowe

~

PLUS

1 2 3

+ -

B A zasilanie

~

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

measuring signals

Sygnały pomiarowe

24V GND

GNDA AL2 AL1 GND

24V

B A zasilanie

RS485

Fig. 4. Electrical connections of the N20PLUS meter

1 2 3

Resistance thermometer RTD

in a two-wire system with manual

compensation

1 2 3

+ -

in a three-wire system with automatic

Thermocouple J, K

Fig. 5. Connections of measurement inputs

The supply must be connected by a two-wire cable, of a suitable wire
diameter, ensuring its protection by means of an installation cut-out.

1 2 3

Resistance thermometer RTD

compensation

1 2 3

Current input
Voltage input

supply

9

5. SERVICE

5.1. Display Description

Alarm

indexes

Fig. 6. Frontal panel

Measured

value

Indexes of actual value

displaying

Highlighted

unit

5.2. Messages after the Supply Connection

After connecting the supply, the meter displays the   X, where
X the letter marking the execution of the meter: U – voltage measure-

ment, I – current measurement, r – measurement of Pt100 temperature,
t – measurement of the temperature by thermocouples, s – custom-made
execution. Next, the program version is displayed in the shape r x.xx –
where x.xx is the number of the actual program version or the number of
the custom-made execution.
Till the time to obtain the required number of correct measurements (acc.
to the table 1), the actual value from the measurement 1 is displayed,
signaled by the highlighted index of the actual value.

In case of an error occurrence or an over ow of the range value, a mes-

sage described in the section 7 will be displayed on the display.

Over ows of the measuring range are additionally signaled by the actual

value signal index.

10

5.3. Meter Configuration

The free eCon software (available at www.lumel.com.pl) is destined for

the N20PLUS meter conguration. The meter should be connected to a

PC computer via the RS485 to USB converter, e.g. PD10, and then in the
E-Con program, select the transmission parameters according to those
set in the meter.

CAUTION! One must carry out the programming of meter parameters
when measuring circuits are switched off!

5.4. Parameters description

5.4.1. Display settings

After choosing the group: - Display settings, following elements are
possible to be congured:

a) display colours of the measured value. The displayed range is divided

into three zones separated by KpL and KpH values (suitably the lower
threshold KpL and the upper threshold KpH of display colour change

– g.9). The colour of displayed numbers for each zone is selected

from three accessible colours: green, orange and red. KpL and KpH
values are set by the user and concern the displayed value (i.e. taking
also into consideration the individual characteristic). The manufacturer
value KpL is equal 100% of the rated value, however KpH is equal
105% of the rated value, e.g. for a 10 V meter execution they are
respectively: for KpL – 10 V and for KpH – 10.5 V.

Caution! After setting the individual characteristic, KpL and KpH
values are not automatically updated.

KpH

KpL

displayed value

Fig. 7. Display color conguration

11

b) decimal point – measurement precision. We have 5 possible display

congurations at choice.

When choosing, one must follow the measurement precision, e.g.:
for the 10 V range – the measurement error is 0.02 V, so the choice
of precision with three places after the decimal point does not give
more precise measurements. When manufacturing, for executions
with voltage and current measurements, the precision 000.00 is set;
for executions with Pt100 temperature measurement – 0000.0; for
execution with the temperature measurement through thermocouples
– 00000.

c) unit highlight. The unit highlight can be enabled or disabled. When

manufacturing it is enabled.

5.4.1. Measurement settings

We can congure the measurement by changing the following elements:

a) Compensation (of terminal temperatures in the version with thermo-

couple measurement or resistance of wires for the version with Pt100
measurements). The switching of the automatic compensation off,
enables to give terminal temperature values or the wire resistance

used in calculations. As the resistance, one must give the sum of
both wires. At the beginning, the compensation is switched by the

manufacturer on.

b) Averaging time: till the time to obtain the required number of correct

measurements (according to the table 1), the actual value from 1 mea­surement is displayed. After measuring a denite number of measure­ments, the arithmetic mean of measured measurements is displayed.

Subsequent measurements are added on the principle of “rolling win-

dow”, i.e. the earliest measurement is discarded and the most recently
measured one is put in its place. The measurement of a value beyond

the measuring range causes the display of overow and the start to

count correct measurements from the beginning. The time is set on 1
s by the manufacturer.

12

Table 1

wyświetlana

Averaging

time

0.5 s 2 every 0.5 s

1 s 7 every 0.5 s

3 s 20 every 0.5 s

5 s 33 every 0.5 s

10 s 67 every 0.5 s

15 s 100 every 0.5 s

20 s 133 every 0.5 s

Number of

averaging time

Updating of displayed values

c) thresholds of displayed overows: one can narrow limits beyond which

overows will be displayed, taking into consideration the individual

characteristic.When the measured value is beyond 0…110% of the
rated value (e.g. for the 10 V execution, it is the range -1…11 V),

the overow is displayed. In manufacturing conditions, the range

–19999…99999 is set.

d) switching the individual characteristic on. In manufacturing conditions

the characteristic is switched off.

The conguration of the individual characteristic consists in dening

the points of the linear characteristic used to convert the measured
value into the displayed value (Figure 8).

displayed

wartość

value

Y2

Y1

X1 X2 wartość mierzona

measured value

Fig. 8. Individual characteristic

13

For example, to get values in kV, set points X1, X2, Y1, Y2 as follows:

y=A⋅x+B

Rys. 8. Charakterystyka indywidualna

X1 = 0, Y1 = 0, X2 = 10, Y2 = 1

y=A⋅x+B

A

=

Y

1−Y

2

X

1−X

2

B=Y1−

Y

1−Y

2

X

1−X

2

⋅X1

X1 X2 wartość mierzona

Y2

Y1

wartość

wyświetlana

X1 = 0, Y1 = 0, X2 = 10, Y2 = 1

This record means that for each measured value in the range
0 ... 10, the displayed value in the range 0 ... 1 will be calculated.

Having the points X1, Y1, X2, Y2, the coefcients A and B of the straight

line with the equation should be determined

according to the rule:

Coefcients A and B are individual characteristic parameters.

5.4.3. Setting of Alarm Parameters

Two alarms are available in the N20PLUS meter. Both alarms
are working independently and each of them has 6 working modes:

n-on, n-off, on, off, hon and hoff, which are presented on the g. 9. Alarm
thresholds Aoff and Aon are set in values of the measured quantity taking

into consideration the individual characteristic. In manufacturing conditions
both alarms are set on the n-on mode.

Additionally, for each alarm, you can set the parameter for the

delay of switching the state.

a) n-on

b) n-off

14

c) on

d) off

Fig. 9. Alarm types: a) n-on, b) n-off, c) on, d) off

Remaining types of the alarm: h-on – always switched on;
h-off – always switched off.

5.4.4. Communication Parameters

The N20PLUS meter is equipped with an isolated
RS-485 interface and communication takes place via the Modbus RTU

protocol. The following parameters are available to congure the correct

communication:

- address on the Modbus, can take values from the range 1 ... 247

- baud rate, are available: 4800, 9600, 19200, 38400, 57600,
115200 bps

- transmission mode, available for selection: 8N2, 8E1, 8O1, 8N1

15

5.4. Manufacturer Parameters

Table 2

Parameter description Range/value Manufacturer value

Display colour of the measured
upper value

Display colour of the measured
middle value

Display colour of the measured
lower value

Upper threshold - KpH -19999…99999

Lower threshold - KpL -19999…99999

Decimal point

Highlight of the measured unit switched off, switched on switched on

Automatic compensation of

the terminal temperature/wire
resistance

Manual compensation value:

terminal temperature
wire resistance
in other cases

Averaging time

Upper overow of the

measurement

Lower overow of the

measurement

Individual characteristic switched off, switched on switched off

Parameter a of the individual
characteristic

Parameter b of the individual
characteristic

red, green, orange red

red, green, orange orange

red, green, orange green

105% of rated value Un,

In or 200°C

100% of rated value Un,

In, or 100°C

00000, 0000.0, 000.00,

00.000, 0.0000,

switched off, switched on

-20…60°C

0…20 Ω

0

0.5 s, 1 s, 3 s; 5 s, 10 s,
15 s, 20 s,

-19999…99999 99999

-19999…99999 -19999

-19999…99999 1

-19999…99999 0

000.00 for U,I, 00000 for
thermocouples J and K

0000.0 for Pt100

switched on (for Pt100,

thermocouples J and K),

switched off for other

executions

40°C

0 Ω

0

1 s

16

Action mode of the alarm output 1

Upper value of the alarm 1

switching - Aon

Lower value of the alarm 1

switching - Aoff

Delay of the alarm 1 switching
time

Action mode of the alarm output 2

Upper value of the alarm 2

switching - Aon

Lower value of the alarm 2

switching - Aoff

Delay of the alarm 2 switching
time

Modbus device address 1...247 1

Baud rate

Transmission mode 8N2, 8E1, 8O1, 8N1 8N2

n-on, n-off, on, off, h-on,

h-off

-19999…99999

-19999…99999

0…120 0 second

n-on, n-off, on, off, h-on,

h-off

-19999…99999

-19999…99999

0…120

4800, 9600, 19200,

38400, 57600, 115200

105% of rated value Un,

100% of rated value Un,

105% of rated value Un,

100% of rated value Un,
In, or 100°C

0 second

9600

n-on

In, or 200°C

In, or 100°C

n-on

In, or 200°C

17

6. MAP OF MODBUS REGISTERS

In the N20PLUS meter, the data is placed in 16 and 32 bit registers.
Parameters and measured values of the meter are placed in the address
space in a way depending on the variable value type. In 16-bit registers,
bits are numbered from the youngest to the oldest (b0-b15). 32-bit regis-

ters contain oat numbers. The list of available registers is presented in

Table 3. The ranges of changes in the value of registers are presented
in tables 4 and 5.

Address range Value type Description

4000 - 4023 Integer (16 bits) Configuration of meter operation

7600 - 7609 Float (32 bits) Configuration of meter operation

7610 - 7611 Float (32 bits) Measured values (oating point). Value

Address

4000 RW Decimal point of the display

4001 RW Unit backlight 0 – off

4002 RW Display color for values below

Register

type

(display precision)

the KpL threshold (Fig. 7) set
in register 7603

parameters (fixed-point parameters).
Value placed in one 16-bit register.

parameters (oating point parameters).

Value placed in one 32-bit register.

placed in one 32-bit register.

Description Changes range

0 - 00000
1 - 0000.0
2 - 000.00
3 - 00.000
4 - 0.0000

1 – on

0 - orange
1 - red
2 - green

Table 3

Table 4

18

4003 RW Display color for values

between KpL and KpH
thresholds (Fig. 7) set in
registers 7602 and 7603

4004 RW Display color for values above

the KpH threshold (Fig. 7) set
in register 7602

4005 RW Alarm type 1 (section 5.4.3) 0 – n-on

4006 RW Alarm 1 delay time 0...120

4007 RW Alarm type 2 (section 5.4.3) 0 – n-on

4008 RW Alarm 2 delay time 0...120

4009 RW Switching on of individual

characteristics.Characteristics
parameters placed in registers
7600 and 7601

4010 RW Averaging time (section 5.4.2 b) 0 – 0.5 s

4011 RW Temperature compensation

mode of terminal / wire
resistance

0 - orange
1 - red
2 - green

0 - orange
1 - red
2 - green

1 – n-off
2 – on
3 – off
4 – hon
5 – hoff

1 – n-off
2 – on
3 – off
4 – hon
5 – hoff

0 – individual char. off
1 – individual char. on

1 – 1 s
2 – 3 s
3 – 5 s
4 – 10 s
5 – 15 s
6 – 20 s

0 - manual, value in
reg. 7610
1 - automatic

19

4012 R Restoring factory parameters

of the meter

4013 R The meter status, read only

value, represents the current
operating status.

4014 RW reserved Not applicable

4015 R reserved Not applicable

4016 R reserved Not applicable

4017 R reserved Not applicable

4018 R Meter’s serial number (older

16 bits of 32-bit value)

4019 R Meter’s serial number

(younger 16 bits of 32-bit
value)

4021 RW Baud rate (change requires

acceptance by writing to
registry 4023)

4022 RW Transmission mode (change

requires acceptance by writing
to registry 4023)

4023 RW Application of transmission

parameters.

0 - do not do anything
1 - restore parameters

Not applicable

Not applicable

0 – 4800
1 – 9600
2 – 19200
3 – 38400
4 – 57600
5 – 115200

0 – 8N2
1 – 8E1
2 – 8O1
3 - 8N1

0 - do not do anything
1 - apply changes

20

Table 5

Address

7600 RW Parameter A of the individual

7601 RW Parameter B of the individual

7602 RW Value of exceeding the upper

7603 RW Value of exceeding the lower

7604 RW Upper alarm trigger threshold 1 -19999…99999

7605 RW Alarm trigger lower threshold 1 -19999…99999

7606 RW Upper alarm trigger threshold 2 -19999…99999

7607 RW Alarm trigger lower threshold 2 -19999…99999

7608 RW The upper threshold for the color

7609 RW The lower threshold for the color

7610 R Value for manual temperature

7611 R Measured value of the input signal Not applicable

Register

type

Description Changes range

-19999…99999

characteristic (section 5.4.2.d)

-19999…99999

characteristic (section 5.4.2.d)

-19999…99999

display value

-19999…99999

display value

-19999…99999

change of the KpH display (section

5.4.1.a)

-19999…99999

change of the KpL display (section

5.4.1.a)

-20..60
compensation of terminals / wire
resistance

21

7. ERROR CODES

After connecting the meter to the network, messages about errors may

appear. Causes of errors are presented below:

Overow of the upper value of the programmed indica-

tion range. In the option with Pt100, it also signals the
incorrect connection of the wire to the terminal 4.

Overow of the lower value of the programmed indica-

tion range.

ErrCA Loss of meter calibration values – In such a case, one

ErrEE Incorrect values in meter conguration data. One must

must contact an authorized service workshop.

set up again meter parameters by means of the eCon
software.

22

7. TECHNICAL DATA

Measuring ranges:

INPUTS:

Measuring ranges of Un voltage:

-165 mV...-150 mV...150 mV...165 mV

-1 mV...0 mV...150 mV...165 mV

-82,5 mV...-75 mV...75 mV...82.5 mV input resistance > 1 M

-1 mV...0 mV...75 mV...82.5 mV

-1 V... 0 V...10 V...11 V

-11 V... -10 V...10 V...11 V

Measuring ranges of In current:

-1...0... 20...22 mA input resistance 10   1%

3.6...4... 20...22 mA input resistance 10   1%

-22...-20... 20...22 mA input resistance 5   1%

Temperature measurement
through Pt100: - 50... 400°C
current owing through
the sensor < 300 mA

Resistance of wires connecting
the resistance thermometer to
the meter: £ 10  (of one wire)

Temperature measurement
through thermocouple J: - 50...1200°C

Temperature measurement
through thermocouple K: - 50...1370°C

Preheating time: 30 min.

Intrinsic error
(at manufacturer settings):  (0.2% of the range 1 digit)

23

Additional errors in rated
operating conditions:

- compensation of reference
junction temperature changes:  0.2% of the range

- compensation of wire
resistance changes:  0.2% of the range

- from ambient temperature
changes:  (0.1% of the range/10 K)

Averaging time: £ 0.5s (1s by default)

Alarm outputs: outputs of OC type (30 V, 20 mA),

passive outputs acc. to EN 62053-31

Output to supply external
transducers: 24 V  5%, 30 mA

Serial interface: RS-485, address 1..247

mode: 8N2, 8E1, 8O1, 8N1
baude rate: 4.8, 9.6, 19.2, 38.4, 57.6, 115.2 kbit/s
transmission protocol: modbus RTU
time to start the answer: 100 ms

Rated operating conditions:

- supply voltage: 85...253 V a.c. (45...65 Hz) or d.c.

20...40 V a.c. (45...65 Hz) or d.c.

- ambient temperature: - 10...23...55°C

- storage temperature: - 25... + 85°C

- relative air humidity: < 95% (inadmissible condensation
of water vapour)

- working position: any

Sustained overload capacity

(measurement of voltage, current): 10%

24

Short duration overload
capacity (3 s):

- sensor inputs 30 V

- voltage input 10 Un

- current input 10 In

Readout eld 5-digit three-colour LED displays:

- digit height: 14 mm,

- colours: green, orange, red

- indication range: -19999...99999

Ensured protection grade
from frontal side IP 65 acc. EN 60529

Overall dimensions 96  48  64 mm (with terminals)

+0.6

Cut-out dimensions in panel 92

 45

+0.6

mm

Weight < 0.25 kg

Power consumption < 6 VA

Galvanic isolation between:

– supply - measuring input 3.2 kV d.c.

Electromagnetic compatibility:

– noise immunity acc. to EN 61000-6-2
– noise emission acc. to EN 61000-6-4

Safety requirements acc. to EN 61010-1 standard:

– isolation between circuits basic
– installation category III
– pollution degree 2
– maximal phase-to-earth

working voltage:

– for supply circuit 300 V (at supply 85...253 V),
– for measuring input 50 V,
– for input destined for programming 50 V.

– altitude above sea level: < 2000 m

25

9. ORDERING CODES

Input:
Pt100: -50...400 °C 1
Thermocouple J: -50...1200 °C 2
Thermocouple K: -50...1370 °C 3

0...20 mA 4

4...20 mA 5

 20 mA

0...75 mV 7

0...10 V 8

 10 V

0...150 mV A

 75 V

 150 V

Supply:

85...253 V a.c./d.c. 1

20..40 V a.c./ d.c. 2

Unit:

unit code number acc. to table 7 XX

Version:

standard 00
custom-made XX

Language:

Polish P
English E

Acceptance test:

without additional quality requirements 0
with an extra quality inspection certicate 1
with an extra calibration certicate 2
acc.to customer’s request* X

N20PLUS X X XX XX X X

6

9

B

C

Table 6

* only after agreeing with the manufacturer

26

Code of the highlighted unit Table 7

Code Unit Code Unit

00 without unit
01 V

02 A

03 mV
04 kV

05 MA
06 mA
07 kA
08 MA

09 °C
10 °F
11 K
12 Hz
13 kHz

14 Ah
15 kAh

16 m/s
17 mm
18 mm
19 cm
20 m
21 km
22 l
23 l/s

1)

- After agreeing with the manufacturer

24 l/h
25 ms
26 s
27 h
28 N
29 kN
30 Pa
31 hPa
32 kPa
33 MPa
34 bar
35 rad
36 
37 k
38 %
39 °
40 rev.
41 rps
42 rpm
43 rph
44 m/h
45 km/h
46 imp
XX on order

1)

ORDERING EXAMPLE:

The Code N20PLUS 910100E0 - means: N20ZPLUS meter with voltage
input on  10 V, supply 85... 253 V a.c., standard version, user’s manual
in English, without aditional quality requirements. Unit„V”

27

28

LUMEL S.A.

ul. Sulechowska 1, 65-022 Zielona Góra, POLAND
tel.: [phone], fax [phone]
www.lumel.com.pl

Export department:

tel.: [phone]
fax.: [phone]
e-mail: [email protected]

N20PLUS-09