TECSYSTEM NT538 ETH User manual

1MN0122 REV. 0
operates with ISO9001 certified quality system
http://www.tecsystem.it
R.1.7 01/08/19
“Translations of the original instructions”
TECSYSTEM S.r.l.
20094 Corsico (MI)
Tel.: [phone]
Fax: [phone]
NT538 ETH
INSTRUCTION MANUAL
ENGLISH

2
NT538 ETH
PAGE
1) SAFETY REQUIREMENTS
……….......................................
4
2) ACCESSORIES
…………………………………..
5
3) TECHNICAL SPECIFICATIONS
…………………………………..
6
4) FRONT PANEL
…………………………………..
8
DISPLAY
…………………………………..
9
OPERATING PROGRAM CONTROL
………………………………….
—
NOTES ON SCAN AND MAN FUNCTIONS
…………………………………..
—
LED TEST
…………………………………..
—
ALARM RELAY TEST
…………………………………..
—
ALARM RELAY SILENCING
…………………………………..
—
5) MOUNTING
…………………………………..
10
6) ELECTRICAL CONNECTIONS
…………………………………..
11
NT538 ETH BACK
…………………………………..
—
POWER SUPPLY
…………………………………..
12
ALARMS AND VENTILATION
…………………………………..
—
FAULT AND RESET MESSAGE SEQUENCE
…………………………………..
—
7) PROGRAMMING
…………………………………..
13
NT538 ETH
…………………………………..
—
PROGRAMMING NOTES
…………………………………..
14
TEMPERATURE SENSORS
…………………………………..
15
MEASUREMENT SIGNAL TRANSFER
…………………………………..
—
TEMPERATURE SENSOR DIAGNOSTICS
…………………………………..
16
VOTING FUNCTION
…………………………………..
—
PROGRAMMED DATA DIAGNOSTICS
…………………………………..
17
TEMPERATURE DIAGNOSTICS
…………………………………..
—
COOLING FAN CONTROL
…………………………………..
—
FAN TEST
…………………………………..
—
CONTENTS
INTRODUCTION
First of all we wish to thank you for choosing to use a TECSYSTEM product and recommend you read this instruction
manual carefully: You will understand the use of the equipment and therefore be able to take advantage of all its
functions.
ATTENTION! THIS MANUAL IS VALID AND COMPLETE FOR THE NT538 ETH CONTROL UNIT

3
NT538 ETH
PAGE
8) ETHERNET MODBUS TCP OUTPUT
…………………………………..
18
INTRODUCTION TO THE ETHERNET MODULE
…………………………………..
—
OPERATING NOTES
…………………………………..
—
DATA TRANSMISSION
…………………………………..
—
NOTES ON ETHERNET ELECTRICAL
CONNECTIONS
…………………………………..
—
FUNCTION CODE
…………………………………..
—
CODE 3(10).
…………………………………..
—
CODE 16(10).
…………………………………..
—
NOTES FOR REMOTE PROGRAMMING
…………………………………..
19
ERROR CODES
…………………………………..
—
ILLEGAL DATA
…………………………………..
20
MODBUS MAPPING TABLE
…………………………………..
—
9) ETHERNET MODULE PARAMETER PROGRAMMING
…………………………………..
26
ETH0 CONNECTIONS
…………………………………..
—
TELNET ENABLING
…………………………………..
—
TELNET SCREEN
…………………………………..
27
IP PARAMETER PROGRAMMING MENU
…………………………………..
28
10) FAIL SAFE FUNCTION
…………………………………..
30
11) Pt100 EXTENSION CABLE TECHNICAL
SPECIFICATIONS
…………………………………..
31
12) FCD FUNCTION
…………………………………..
—
13)WARRANTY CONDITIONS
…………………………………..
32
14)TROUBLESHOOTING
…………………………………..
—
15)EQUIPMENT DISPOSAL
…………………………………..
—
16)USEFUL CONTACTS
…………………………………..
33
17) UL SPECIFICATION AND RATINGS
…………………………………..
—

4
NT538 ETH
SAFETY REQUIREMENTS
ATTENTION:
Carefully read the manual before starting using the control unit. Keep the instructions for future reference.
Do not open the device, touching any internal component can result in electric shock as voltages over 50 volts
can be lethal. In order to reduce the risk of electric shock, do not disassemble the back of the device. Warranty shall be
void if device is opened.
Before connecting the device to the power supply, ensure that all the connections are correct. Always disconnect
the unit from the supply before making any modification on the wiring.
Any operation on the equipment must be operated by a qualified technician.
Failure to comply with these instructions can cause damages, fires or electric shock, and possible serious
injuries!
POWER SUPPLY
The NT538 ETH can be supplied from 85 to 260 Vac-Vdc, irrespectively of polarity in Vdc. Before use, ensure that the
power cable is not damaged, knotted or pinched. Do not tamper with the power cable. Never disconnect the unit by
pulling the cable, avoid touching the clamps. Do not carry out any connecting/disconnecting operation with wet hands. To
disconnect the device, do not use objects such as levers. Immediately disconnect the device if you smell burning or see
any smoke: contact technical service.
LIQUIDS
Do not expose the equipment to liquid spurts or drops, do not position it in places where humidity exceeds 90% and
never touch it with wet or humid hands. If any liquid penetrates the control unit, disconnect immediately and contact
technical service.
CLEANING
Disconnect the power cable before cleaning the control unit, using a dry cloth without any solvent or detergent, and
compressed air.
OBJECTS
Never insert objects into the openings of the control unit. If this happens, disconnect the control unit and contact technical
service.
USE RESERVED TO QUALIFIED PERSONNEL
The purchased good is an advanced electronic device that should not be used by non-qualified personnel. Any operation
must be carried out by a qualified technician.
ACCESSORIES
The use of non-original accessories or spare parts may damage the unit and endanger users' safety. In event of fault,
contact technical service.
LOCATION
Install the control unit indoor, in a place protected from water splashes and sun rays. Do not place near heat sources if
exceeding the parameters stated in this manual. Position on a stable surface, far from any possible vibrations. Position
the unit as far as possible from intense magnetic fields.
REPAIRS
Do not open the control unit. In case of fault, always contact qualified personnel. The opening of the control unit and/or
the removal of the series identifying label automatically make the warranty void. The warranty seal is applied to all
devices, any attempt to open the unit would cause the seal to break the consequent automatic cancellation of the
warranty.
FUNCTION
To control the transformer correctly from a temperature point of view, enabling the VOTING function is allowed
where the load distributed between the phases of the transformer is adequately balanced.
TECHNICAL INFORMATION
Mail: [e-mail] —tel: [phone]

5
NT538 ETH
The following objects are present inside the box:
Control unit
Start guide and QR code
2 blocks for panel mounting
1 supply terminal 3 poles pitch 5
Code: 2PL0367- Screws tightening torque 0.5Nm
1 relay terminal 12 poles pitch 5
Code: 2PL0361- Screws tightening torque 0.5Nm
2 Pt100 sensor terminal 12 poles pitch 3.81
Code: 2PL0430 - Screws tightening torque 0.25Nm
ACCESSORIES
ATTENTION: always install the device using the terminals included in the pack.
The use of terminals other than those included with the control unit might cause malfunctions.

6
NT538 ETH
TECHNICAL SPECIFICATIONS
NT538 ETH
POWER SUPPLY
Supply rated values
85-260 Vac-Vdc
50/60HZ
Vdc with reversible polarities
●
INPUTS
8 inputs for RTD sensors, Pt100 type with 3 wires (max section 1.5mm²)
●
Connections on removable terminal strips
●
Input channels protected against electromagnetic interference
●
Cable compensation for thermistors
500m (1mm²)
OUTPUTS
2 alarm relays (ALARM AND TRIP) SPDT
●
1 sensor or operating failure (FAULT) relay SPST
●
Output relays with 10A-250Vac-res COSФ=1 contacts.
●
2 ventilation management relays SPST FAN 1 AND FAN 2
●
Ethernet output 10Base T / 100Base-TX Modbus TCP slave.
●
DIMENSIONS
100x100 mm–din43700-depth 131mm (terminal block included)
Hole 92 x 92 mm
TESTS AND PERFORMANCE
Construction in compliance with CE regulations
●
Protection from electrical interference EN 61000-4-4
●
Dielectric strength 1500 Vac for a min. between output relays and sensors, relays and power
supply, power supply and sensors
●
Accuracy ±1% vfs, ±1 digit
●
Ambient operating temperature from –20°C to +60°C
●
Humidity 90% non-condensing
●
Frontal film polycarbonate IP65
●

7
NT538 ETH
TECHNICAL SPECIFICATIONS
NT538 ETH
Housing NORYL 94 _V0
●
Absorption 7,5VA
●
Digital linearity of sensor signal
●
Self-diagnostic circuit
●
Protection treatment of the electronic part
Option
DISPLAY AND DATA MANAGEMENT
2x13mm displays with 3 digits to display temperatures, messages and channels
●
3 LEDs to display the state of the alarms of the selected channel (ALARM-TRIP-FAULT)
●
4 leds selection of display mode (SCAN-AUTO-MAN-T-MAX)
●
2 LEDs to display the state of FAN1 and FAN2
●
Temperature control from 0°C to 240°C (*)
●
1 alarm thresholds for each channels
●
1 Trip thresholds for each channels
●
2 ON-OFF thresholds for FAN 1 and FAN 2 in common for all enabled channels
●
Sensor diagnostics (Fcc-Foc-Fcd)
●
Data memory diagnostics (Ech)
●
Access to programming through front keyboard
●
Automatic exit from relay programming, display and test after 1 minute's inactivity
●
Incorrect programming warning
●
Selection between channel automatic scanning, hottest channel or manual scanning
●
Storage of maximum temperatures reached by channels and alarm status
●
Front key to reset the alarms
●
Voting function
●
Fail Safe function
●
(*) On demand, available version from -40°C to 200°C with alarm temperature management range from 0°C to 200°C

8
NT538 ETH
1)
3-digit temperature display
12)
Enter/Reset button
2)
Control unit series
13)
Programming / Setting key
3)
TRIP (red) LED
14)
LED/relay test key
4)
ALARM (yellow) LED
15)
RS (green) LED
5)
FAULT (red) LED
16)
3-digit channel display
6)
FAN 1 (yellow) LED
17)
T-max mode selection (red) LED
7)
FAN 2 (yellow) LED
18)
Man mode selection (yellow) LED
8)
Display mode selection key
19)
Auto mode selection (green) LED
9)
Fixing block
20)
Scan mode selection (yellow) LED
10)
UP key
21)
Fixing block
11)
DOWN key
FRONT PANEL
1
2
3
4
5
6
7
8
9
10
11
12
14
13
15
16
17
18
19
20
1MN0122 REV. 0
21

9
NT538 ETH
DISPLAY
The first display is dedicated to temperatures.
The second display to the monitored channel.
When the device is switched on or after a reset, the model of the control unit, the type of sensors, VER "00" (firmware
version), the temperature range of the device and the unit identification are always shown on the display.
Pressing the MODE key, the display modes can be set:
SCAN: the monitoring unit displays all the activated (°C) and deactivated (NO) channels scanning every 2 seconds.
AUTO: the monitoring unit displays the hottest channel automatically.
MAN: manual reading of the channel temperature using the up/down keys 
T.MAX:The display shows the maximum temperature of the channel selected with the cursor keys. In the event of fault,
the Tmax value is replaced with the type of fault stored (fcc-foc-fcd). Turning ON of the leds Trip-Alarm-Fault LEDs alerts
us to events that have occurred. The stored values are always successive to the moment of the last T-MAX reset, for
resetting the values press the RESET key.
OPERATING PROGRAM CONTROL
To control the protection levels programmed, press the PRG key twice to access the VIS display mode.
By repeatedly pressing the PRG key, you can scroll through all the previously loaded values in sequence.
After 1 minute's keyboard inactivity, the programming display procedure is automatically abandoned.
To stop the display, press the ENT key.
NOTES ON SCAN AND MAN FUNCTIONS
During the SCAN and MAN modes, the operation of the NT538 can be displayed.
1) RUN cPU:
This message appears when the device is turned on.
2) Ech Err:
This message appears when a damage in the EEPROM memory is detected.
Pressing Reset will cancel the message and restore the original default parameters, listed in the programming
paragraph on pages 13-14. Return the control unit to TECSYSTEM for repairs.
3) CAL Err:
This message appears when damage is found in the measurement circuit.
The temperature values displayed might be incorrect. Return the control unit to TECSYSTEM for repairs.
4) Pt Err :
This message appears when it is detected that one or more PT100 sensors are not working correctly, FOC, FCC
and FCD indications in the temperature sensor diagnostics paragraph on page 16.
In case of Err the FAULT relay will be de-energised.
The above messages will be displayed following the 1-2-3-4 priority stated.
NOTE: regardless of the display mode, in case of a sensor fault (fcc, foc or fcd), the control unit will automatically switch to
SCAN (PRIVILEGED SCAN) mode, immediately allowing you to see the fault on the relative channel CH.(Mode key is
disabled).
LED TEST
We suggest carrying out the control unit LED test regularly.
For this operation, press the TEST key briefly; all the displays turn on for 2 seconds.
If one of the LEDS does not work, please return the control unit to TECSYSTEM for repair.
ALARM RELAY TEST
This function allows you to carry out a test of the relay operation without having to use further devices. To start the test
procedure, keep the TEST button pressed for about 5 seconds: TST appears for 2 seconds, confirming you have entered the
Relay Test mode.
The LED that is lit shows the relay to be tested; use the cursors to select the desired relay.
Press the SET and RESET keys to energise and de-energise the relay to be tested; the display will show ON-OFF.
After 1 minute's keyboard inactivity, the RELAY TEST procedure will be automatically abandoned.
To stop the RELAY TEST procedure, press the TEST key.
Alternatively, you can use the PT100 simulator model: SIM PT100.
ALARM RELAY SILENCING
If you want to silence the ALARM signal press the RESET key: the relay de-energises and the ALARM LED, which was
fixed, will start flashing. Silencing is automatically disabled when the temperature goes below the ALARM threshold.

10
NT538 ETH
Fix the unit securely with the blocks supplied.
1)
Control unit
2)
Panel hole dimensions (+0.8mm tolerance)
3)
Identification label
1)
Control unit
3)
Fixing screw
2)
Fixing block
4)
Cross-head screwdriver #1X100mm
MOUNTING
1
1MN0007 REV. 0
2
3
1
2
3
4
1MN0008 REV. 0
Drill a 92 x 92 mm hole in the panel sheet.

11
NT538 ETH
NT538 ETH
SCREEN RED RED WHITE
ELECTRICAL CONNECTIONS
1
2
3
4
1MN0095 REV. 0
Output relay with 10A-250Vac-res COSФ=1 contacts.
COSФ=1.
STOP
SYSTEM
ALARM
CONDITION AUDIO AND
VISUAL INDICATION
Pt100 CONNECTION EXAMPLE
Note: before connecting the
sensors to the control unit, read
the Measurement signal transfer
paragraph on page 15.
Note: relay contact image in non-alarm condition, with the exception of the FAULT relay that switches: contacts 11-
12 open (NO) contacts 11-12 closed (NC) fault condition identification. Read the Alarms and Ventilation paragraph
on page 12 and see the opening of the fault contact.
.
RELAY CONNECTION EXAMPLE
1)
Pt100 sensors (white-red-red)
3)
Relays (FAN2-FAN1-ALARM-TRIP-FAULT)
2)
Supply 85-260Vac-dc 50/60Hz.
4)
RJ45 Ethernet output, Link-Activity LED, see
indication on page 30.

12
NT538 ETH
POWER SUPPLY
The NT538 ETH control unit can be supplied by 85 to 260 Vac-Vdc, 50/60 Hz irrespectively of polarity in Vdc
(terminals 40-42).
This is obtained thanks to the use of a tested power supply unit, newly designed and manufactured, that frees installers from
worrying about the correct Vac and Vdc supply.
The ground must always be connected to terminal 41.
When the unit is supplied directly by the secondary of the transformer to protect, it can be burnt out by strong
overvoltages.
This happens if the main switch is closed and the transformer has no load (blank test).
The above-mentioned problems are much more evident when the 220 Vac voltage is taken directly from the
transformer secondary bars and there is a fixed capacitor battery to phase the transformer itself.
To protect the control unit from line overvoltages, we suggest using the PT-73- 220 electronic discharger, designed by
TECSYSTEM S.r.l. for this specific purpose. As an alternative we suggest using 110 Vac or, even better, 110 Vdc supply
voltages.
If an existing control unit must be replaced with a new one, to guarantee its correct and safe operation, the
sensor/relay/supply connecting terminals must be replaced with the new terminals supplied.
ALARMS AND VENTILATION
Carry out the electrical connections on the removable terminal blocks only after disconnecting them from the unit.
When the control unit is in one of the modes mentioned below, it does not monitor the temperature and the relays are all
blocked. The fault contact switches and the fault LED flashes.
Vis. programming display
PRG Programming
Relay test
The ALARM and TRIP relays switch only when the set temperature thresholds are exceeded.
The FAULT contact, programmed in failsafe mode (default YES), opens (11-12) when the equipment is supplied only if
the unit detects no fault on switching on, and stays in this condition until one of the following events occurs:
Data memory fault (Ech message).
Pt100 sensor fault (FCC short-circuited sensor, FOC interrupted sensor or Fcd quick temperature increase)
CAL damage to the measurement circuit.
Insufficient supply voltage.
During the power on reset after programming (PRG), displaying the data (VIS) and test relay.
The FAULT failsafe can be disabled FAULT selecting failsafe "NO" see step 30-31 programming page 14.
NOTE: do not connect the FAULT relay to the transformer tripping circuit to avoid unwanted system interruptions.
FAULT AND RESET MESSAGE SEQUENCE
Find below the sequence of fault messages and RESET function condition.
1) ECH
2) CAL
3) FCD
4) ERR PT
The FAN1 and FAN2 contacts can be used to control the cooling fans, or they can be inserted in the conditioning system of
the transformer room, see paragraph Fan control on page 17.
NOTE: always disconnect the unit before performing any electrical connections.
11 12
FAULT 11-12 NC: ALARM FAULT OR POWER OFF
FAULT 11-12 NO: POWER ON OR NO FAULT
11 12
FAULT CONTACT
eeprom fault
measurement circuit fault
quick temp. increase fault
FCC or FOC sensor fault
erasable message
erasable message
resettable condition
non-resettable condition

13
NT538 ETH
PROGRAMMING
NT538 ETH
STEP
PRESS
EFFECT
PRESS
NOTES
1
Keep the PRG key pressed until the display shows PRG
SET
2
Select PRG SET for entering in the programming mode or
PRG 1 to restore the default programmed value.
PRG 1 default value
3
it is displayed the CH1 activation
YES = CH1 Enable
NO = CH1 Disable
4
Select YES or NO
5
The ALARM CH1 threshold for is displayed Set the
desired threshold, the Alarm LED flashes
Default 90°C
6
Set the desired threshold
7
The TRIP CH1 threshold for is displayed Set the desired
threshold, the Trip LED flashes
Default 119°C
8
Set the desired threshold
9
it is displayed the CH1 FAN activation,
FAN1 and FAN2 ARE flashing
info functioning fans : fan
control section page 17
10
Select : YES + FAN1 FAN2 enabled flashing
YES only FAN1 enabled flashing
YES only FAN2 enabled flashing
NO LED FAN1- FAN2 off
Default YES FAN1+FAN2
11
Repeat the above steps for all channels
CH2 - CH8
12
The display shows ON this indicator flashes FAN1
Default 70°C
13
Set the desired threshold
14
The display shows OFF this indicator flashes FAN1
Default 60°C
15
Set the desired threshold
16
The display shows ON this indicator flashes FAN2
Default 45°C
17
Set the desired threshold
18
The display shows OFF this indicator flashes FAN2
Default 35°C
19
Set the desired threshold

14
NT538 ETH
20
HFN (NO) is displayed
The FAN1-FAN2 LEDs flash
Fan cyclic test
for 5 min. every “n” hours
21
Set the desired number of hours
Default NO = function disabled
22
FCD (NO) is displayed
Fault for quick temperature
increase (°C/sec)
23
Set the desired value
(FCD info on page 31)
Default NO
(function excluded)
24
VOT (NO) is displayed
(VOTING info on page 16)
25
Select the NO-1-2-3
Default NO
(function excluded)
26
The display shows FLS (ALARM)
Blinking LED ALARM
(info FAIL SAFE on page 30)
27
Select YES or NO
Default NO
28
The display shows FLS (TRIP)
Blinking LED TRIP
29
Select YES or NO
Default NO
30
The display shows FLS (FAULT)
Blinking LED FAULT
31
Select YES or NO
Default YES
32
END is displayed
End of programming
33
Press ENT to save the set data
and exit programming
Err: incorrect programming of
the LED values (note 6)
34
Return to step 1
PROGRAMMING NOTES
1) The MODE key allows reversing the programming steps according to the sequence 24-22-12-1
2) The TEST key allows exiting programming without saving the modified data.
3) After 1 minute's keyboard inactivity programming is abandoned without saving the data.
4) During programming the control unit does not control/protect the monitored machine.
5) At the end of programming the control unit is restarted and the FAULT relay is disabled until the unit is fully restarted.
6) If pressing ENT, “Err” appears, it means that one of the following mistakes has been made:
ERR ALL. = ALARM ≥TRIP (CH1-CH2-CH3-CH4-CH5-CH6-CH7-CH8)
ERR FAN = FAN-OFF ≥FAN-ON. (FAN1 OR FAN2)
The device automatically switches to the programming step of the mistake.
NOTE: EVERY TIME THE CONTROL UNIT IS PROGRAMMED WITH DATA SAVING CONFIRMATION, THE VALUES
STORED IN T-MAX ARE RESET TO THE TIME OF SAVING.
ATTENTION :
We recommend you check the unit's programming before starting the device.
The default parameters set by TECSYSTEM might not match your requirements.
Programming the device is the end user's responsibility, the settings of the alarm thresholds and the enabling of
the functions described in this manual must be checked (by a specialized engineer) according to the application
and features of the system the control unit is installed on.

15
NT538 ETH
All "NT" series control units have linearity of the sensor signal, with a maximum error of 1% of full scale value.
TEMPERATURE SENSORS
Each Pt100 temperature sensor has a white wire and two red ( CEI 75.8 ) , in the figures on page 11 shows the disposition
of the in the terminal and connection cables. Each channel can be independently programmed with two alarm thresholds
(alarm and trip).
MEASUREMENT SIGNAL TRANSFER
All the cables transferring the Pt100 measurement signals must comply with the following under all circumstances:

1. Every Pt100 must be connected with a three-wire cable having a minimum section of 0.35mm² and a maximum of 1 mm².
2. The extension cable must be screened with tinned copper braid with an 80% cover
3. Conductors must be twisted, maximum recommended step 60mm
4. The cable screening must be grounded only with a termination, preferably on the unit side.
5. The sensors' signal transfer cable must not be near electrical cables, either low or medium-high voltage.
6. The Pt100 cable and the signal transfer cable must be laid in a straight line, without any winding.
7. Any caps used to butt conductors must be crimped properly to avoid false contacts.
NOTE: to install the sensors and signal transferring cable correctly, read the SCS/SENSOR installation rules
manual.
What may happen when installation rules are not complied with.
1)The electrical field propagating from the power line of another circuit, couples capacitively with the conductors (in
particular with unscreened cables). The effect of this coupling creates a signal that overlaps the signal transmitted by the
nearby conductors, causing incorrect readings.
2) The variations in magnetic flux in the power lines may induce an electromotive force on the signal transferring cables (in
particular non-twisted cables), that, being a closed circuit, generates a current. This interference current, multiplied by the
circuit resistance, gives a voltage value that overlaps the signal to be transmitted, distorting the sensor measurement.
3) False contacts can alter the signal with the consequent variation in the temperature detected.
In specific cases, when the rules for connecting the Pt100 sensors are not complied with, the following anomalies can
occur between the SCS box and the temperature control unit:
a) incorrect temperature readings, alarms or anomalous tripping
b) mechanical / electrical fault of the Pt100 sensors
c) damage to the Pt100 inputs of the control unit.
TECSYSTEM S.r.l. has designed its own special cable to transfer the measurement signals, CEI-compliant, with all the
protection requirements provided for: model CT-ES
NOTE: the use of cables not complying with the above might cause reading anomalies. It is always important to
take into account that any interference on the signal lines might cause anomalies on the Pt100 inputs (CH1-
CH2-CH3-CH8...) or on the sensors themselves.

16
NT538 ETH
TEMPERATURE SENSOR DIAGNOSTICS
In case of failure or exceeded full scale value of one of the thermometric sensors installed on the machine to protect, the
FAULT relay opens immediately with the relative warning of faulty sensor on the corresponding channel (PT err).
Fcc indicates sensor short-circuited or minimum full scale value of the control unit exceeded -8°C (version 0°÷240°C)
and -48°C (version -40°C÷200°C)
Foc indicates sensor interrupted or maximum full scale value of the control unit exceeded 243°C (version 0°÷240°C)
and 203°C (version -40°C÷200°C)
To eliminate the message and reset the opening of the Fault contact, it is necessary to check the Pt100 connections and
replace the faulty sensor (if any). If the minimum/maximum full scale value has been reached, check that the ambient
conditions match the control unit reading.
Note: exceeding the minimum/maximum full scale value can also be caused by interference on the sensor lines; in this
case we recommend that you check:
the correct installation of the sensors and above all of the extension cable (as stated in the paragraph MEASUREMENT
SIGNAL TRANSFER)
the activation of: VOTING (see below) or FCD (see page 31) according to the conditions of the system.
CAL message display: it appears when damage is found in the measurement circuit. The temperature values displayed
might be incorrect. Return the control unit to TECSYSTEM for repairs.
VOTING FUNCTION
The voting function is derived from the concept of redundancy which consists of the duplication of components of a system
with the intention of increasing reliability.
How the VOTING works?
Taking advantage of the principle indicated we use the probes installed to monitor the operation of the electrical machine,
but at the same time ensure the proper functioning of the probes themselves, discriminating any false alarms (generated
by installation errors or failures).
Enabling VOTING can be done by choosing one of three modes of selection "1-2-3" the control unit performs a
comparison of the temperature values measured on the channels monitored, enables switching of the tripping contact
(TRIP) only if it is found the overcoming of the TRIP threshold on at least two channels in the same period T.
Selecting VOTING "NO" function will be disabled.
In the tables, the selection, indicated below you will find the combination of channels with voting active available.
For greater flexibility in two combination we expected channel with voting enabled and others with voting disabled.
Voting enabled: The contact TRIP switches only if at least two channels exceeded TRIP threshold.
Voting disabled: The contact switches when the TRIP single-channel exceeds the threshold of TRIP.
Selection 1
Selection 2
Selection 3
VOTING ENABLE CH1…..CH3
VOTING ENABLE CH1 …. CH6
VOTING ENABLE CH1 …. CH8
1
1
1
2
2
2
3
3
3
VOTING DISABLE CH4..CH8
4
4
4
5
5
5
6
6
6
VOTING DISABLE CH7..CH8
7
7
7
8
8
8
Note: The switching of ALARM signal still exceeded the threshold of alarm on each channel.
To enable Voting read the programming section on pages 13-14.
Attention: To control the transformer correctly from a temperature point of view, enabling the VOTING
function is allowed where the load distributed between the phases of the transformer is adequately balanced.
In addition, any conditions of FAULT: FCC-FCC-FCD on two or more channels, with active voting, can
determine the TRIP contact inhibition.

17
NT538 ETH
PROGRAMMED DATA DIAGNOSTICS
In case of failure of the internal memory or corruption of programmed data, just after switching on, Ech appears with the
relevant Fault contact.
In this case, for safety reasons, the default parameters are loaded automatically (see programming table on pages 13-14).
Eliminate Ech by pressing RESET and run programming to enter the desired values.
Finally switch the unit off and back on to check the memory works correctly, if it is damaged Ech will be displayed again
(send the control unit to TECSYSTEM srl for repairs).
TEMPERATURE DIAGNOSTICS
When one of the temperature sensors senses a temperature 1°C higher than the alarm threshold, 5 seconds later the
ALARM relay switches and the ALARM LED of the affected channel (CHn) lights up.
When the trip temperature limit is exceeded, 5 seconds later, the TRIP relay switches and the TRIP LED of the affected
channel (CHn) lights up.
As soon as the recorded temperature returns to values equal to or lower than the limit set for the ALARM and TRIP relays
switching, these relays de-energise and the corresponding LEDs switch off.
The ALARM and TRIP values are kept in the internal memory: they can be recalled by entering the Vis modes
(programmed parameter display) and modified in PRG (programming) mode.
COOLING FAN CONTROL
The unit NT538 ETH has two contacts FAN (FAN1 and FAN2), if properly programmed, can control ON-OFF of fans for
cooling system checked.
The high flexibility of the NT538 ETH allows you to select, for each channel, an operation mode for contact management
of FAN1 and FAN2. During the programming of the individual channel, enabled, you will be asked to select one of the
following ways to activate FAN, dedicated to that channel:
YES FAN1 + FAN2 enabled flashing
The selected channel CHn, enable the switching of both contacts FAN1 and FAN2 in relation to thresholds ON - OFF
programmed for FAN1 and FAN2.
YES only FAN1 enabled flashing
The selected channel, CHn, enable the switching of the contact FAN1 in relation to the threshold ON - OFF programmed
to FAN1.
YES only FAN2 enabled flashing
The selected channel, CHn, enable the switching of the contact FAN2 in relation to the threshold ON - OFF programmed
to FAN2.
NO FAN1 + FAN2 flashing Off
The FAN function on the selected channel, CHn, is disabled. The selected channel is not associated with any threshold
FAN.
The thresholds FAN1: (ON –OFF) and FAN2: (ON –OFF) are common to all channels CHn enabled, programmable to
step 12-19 Programming page 13.
FAN1: (eg. At 70 ° C ON - OFF at 60 ° C)
FAN2: (eg. At 45 ° C ON - OFF at 35 ° C)
The values of ON and OFF can be programmed depending on the range of the device, FAN ON must always be greater
by at least 1 °C since FAN OFF (recommended ΔFAN POWER ON-OFF + 10 ° C).
The FAN 1 / FAN 2 LED light up when the temperature exceeds 1°C the FAN ON threshold, the corresponding relay
switches, and turns off when the temperature goes below 1°C the FAN OFF threshold, the corresponding relay switches.
FAN TEST
By programming (HFn), it is possible to have the fans operating 5 minutes every "xxx" hours, regardless of the column or
ambient temperature values (i.e.: with HFn=001 the fans are activated for 5 minutes every hour).
This function aims at verifying the fan operation and their control apparatus periodically.
By setting NO this function is inhibited.
To enable the HFN function, read the programming section on pages 13-14.
IMPORTANT WARNING
Before carrying out the isolation test of the electrical panel the control unit is installed on, disconnect it together
with the sensors from the power supply to prevent it from being seriously damaged.

18
NT538 ETH
ETHERNET MODBUS TCP OUTPUT
INTRODUCTION TO THE ETHERNET MODULE
The Ethernet connectivity of the new NT538 ETH allows you to implement the functions of the Tecsystem control units
directly into your monitoring system, with maximum 8 Modbus TCP nodes.
The integrated module includes all the essential network features, among which a 10Base T / 100Base-TX Ethernet
connection, TCP / IP full stack suitable to work as Modbus TCP slave.
The unit can be used for remote configuration, monitoring in real time or problem solving.
The Windows-based Telnet system allows configuring the NT538 ETH easily into a sub-network with specific IP
addresses.
OPERATING NOTES
The communication of the temperature control monitoring unit is active only when the NT538 ETH is in temperature
control mode (Scan, Auto, Man and T.Max).
When other functions such as programming, programming display and relay test are activated, the ModBus
communication is temporarily deactivated.
DATA TRANSMISSION
The Ethernet module allows you to connect to the control unit through Modbus TCP slave so that you can: read the data
on the Modbus table on page 20 and write those in the paragraph regarding the remote programming notes.
The ETH module is always in slave mode.
The NT538 ETH control unit is in communication with the network only when it is in temperature reading mode, while it is
inactive when in the following modes: display, programming and relay test.
NOTES ON ETHERNET ELECTRICAL CONNECTIONS
As to the signal cable to use in order to guarantee correct operation, it is necessary to use a CAT 7 Ethernet cable with
RJ45 connector with the following specifications:
4 twisted pairs 23AWG
Tinned copper braid with an 80% cover.
Always position the Ethernet cable far from power cables.
.
FUNCTION CODE
The ModBus module supports the following function codes:
3(10):- holding register reading
16(10):- register multiple writing
If ModBus receives a message and a CRC error is detected, no answer is given.
CODE 3(10).
Request:
Slave address, code 3(10), Starting address HI, Starting address LO, Number of Point HI, Number of Point LO, Crc LO, Crc HI.
Answer:
Slave address, code 3(10), Byte count, Data HI, Data LO……., Crc LO, Crc HI.
CODE 16(10).
Request:
Slave address, code 16(10), Starting address HI, Starting address LO, Number of Point HI, Number of Point LO, Byte count,
Data HI, Data LO……., Crc LO, Crc HI.
Answer:
Slave address, code 16(10), Starting address HI, Starting address LO, Number of Register HI, Number of register LO, Crc LO,
Crc HI.

19
NT538 ETH
NOTES FOR REMOTE PROGRAMMING
The writable registers are shown in TABLE MODBUS MAPPING referred to as W or RW (write or read / write) max number
of registers 72, see table page. 20.
In the case in which the channel is not enabled and / or the information is not provided we have the following answers:
1. Temperatures measured = 0000 (0 ° C)
2. Temperatures AL. / TRP = value written in E2PROM
3. Channel status = 0000
4. Setting channel =% 00000000, xxxxxxx0% (x = na)
If WRITE data must always respect the rule T_trip> T_alarm and FAN_ON> FAN_OFF.
In case you try to set these thresholds incorrectly, the control unit NT538 ETH will not proceed with the programming and
storage of data, therefore in subsequent readings will read the data from the previous schedule.
After having sent a request for writing the control unit will take a time of about 1 '' to store the data in eeprom, during the step
of storing the module ModBus will not be able to process additional requests.
If the demand for programming is successful, the unit automatically resets and loads the new settings.
In the event that information is sent in writing to a register can’t be written (only READ) data will be trashed without affecting
the received message.
The information "RELAY STATUS" indicates the state of excitation of the coils of the relays, so it will be subject to the
commands of "FAIL SAFE".
From the point of view of the control unit Modbus connection is considered as a normal NT538.
At the end of the write command (Write) is carried out a check of compatibility data:
If you have a non-compatibility "exception" for an answer and the data packet is rejected in its entirety. The code
of the first erroneous data can be obtained by reading the log "Error received data" (Note: this code is lost during
RESET or new power or writing data in E2PROM);
if the data are correct, they are transferred to the non-volatile memory (E2PROM), resets the historical data (Tmax
= 0 ° C) and is subsequently forced a reset of the system
If the WRITE command implies only writing "CONTROL" it will be implemented autonomously and without RESET,
ie without affecting the data of the control unit.
ERROR CODES (exception codes)
In case of a wrong request, ModBus will answer with modified codes and codified errors according to the following:
1: - Unsupported function code
2: - Wrong data address
3: - Wrong data (for instance length)
The memory area containing the HFN datum must undergo no forcing.
In the case in which all the fans are turned off (F1, F2) the test of the relay will not take place.
GENERAL UNIT NOTE
The models of the unit can be equipped with different options; to avoid disruption of production their existence is defined by
Fw indicated power , with messages dedicated on display LEDs .
This information can be accessed by reading the Modbus register 6 (options) with the following meaning:
LOW Byte
Bit_1 = Ethernet
HIGH Byte
Bit_0/1 = 00 - Range 0°C ÷ 240°C
Bit_0/1 = 10 - Range -40°C ÷ 200°C
In case of Ethernet option Modbus and 4.20mA mode shall not be active on the display. They will be readable from the log.
Note: in case the values programmed from ModBus are out of range, it will generate a "exeption" error response to
date.

20
NT538 ETH
MODBUS MAPPING TABLE
HEADER (information and commands):
Address
LO (10)
Data HI
Data LO
R: read
W:write
RW:
read/write
1
Modello –MSD (ASCII)
Modello - 3° Digit (ASCII)
R
2
Modello - 2° Digit (ASCII)
Modello –LSD (ASCII)
R
3
Space (20H)
Vers. Fw –MSD(ASCII)
R
4
Vers. Fw - 2° Digit (ASCII)
Vers. Fw –LSD(ASCII)
R
5
Channels qty (2*ASCII)
R
6
Options (see note)
Options (see note)
R
7
00
Wrong datum received
R-see tab.
8
00
Info various causes
R-see tab
9
00
Commands
W-see tab.
ILLEGAL DATA
On the other hand, some combinations are programming errors because they are wrong settings; in this case the error
code is ILLEGAL_DATA. This information is accessible to ModBus reading the register 7.
NO ERROR
CH_1 Trip ≤ Alarm
CH_2 Trip ≤ Alarm
CH_3 Trip ≤ Alarm
CH_4 Trip ≤ Alarm
CH_5 Trip ≤ Alarm
CH_6 Trip ≤ Alarm
CH_7 Trip ≤ Alarm
CH_8 Trip ≤ Alarm
FAN_1 ON ≤OFF
FAN_2 ON ≤OFF
No channels enabled
Value HFN > max see table: SYSTEM - Setting and Status
Value FCD > max see table: SYSTEM - Setting and Status
Value 4.20 > max see table: SYSTEM - Setting and Status
Value Voting > max see table: SYSTEM -Setting and Status
Voting wrong function (channels not enabled)
Note. If the value of Voting is higher than the max value expected for the model in question, it will be set equal to "0", that is
NO_VOTING.
No error 00
Code error 01
Code error 02
Code error 03
Code error 04
Code error 05
Code error 06
Code error 07
Code error 08
Code error 017
Code error 018
Code error 019
Code error 020
Code error 021
Code error 022
Code error 023
Code error 024