Circutor STM-S12 User manual

INSTRUCTION MANUAL
Analyzer of currents and
voltage of photovoltaic Strings
(M329B01-03-21A)
STM-S12, STM-S24, STM-H6,
STM-H10, STM-H20

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STM-S12, STM-S24, STM-H6, STM-H10, STM-H20
Instruction Manual

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Instruction Manual
STM-S12, STM-S24, STM-H6, STM-H10, STM-H20
SAFETY PRECAUTIONS
DANGER
Warns of a risk, which could result in personal injury or material damage.
ATTENTION
Indicates that special attention should be paid to a specific point.
Follow the warnings described in this manual with the symbols shown below.
If you must handle the unit for its installation, start-up or maintenance, the following should be
taken into consideration:
Incorrect handling or installation of the device may result in injury to personnel as well as damage to
the device. In particular, handling with voltages applied may result in electric shock, which may cause
death or serious injury to personnel. Defective installation or maintenance may also lead to the risk of
fire.
Read the manual carefully prior to connecting the device. Follow all installation and maintenance in-
structions throughout the device’s working life. Pay special attention to the installation standards of
the National Electrical Code.
Refer to the instruction manual before using the device
In this manual, if the instructions marked with this symbol are not respected or carried out correctly, it can result
in injury or damage to the device and/or installations.
CIRCUTOR S.A.U. reserves the right to modify features or the product manual without prior notification.
DISCLAIMER
CIRCUTOR S.A.U. reserves the right to make modifications to the device or the unit specifications set
out in this instruction manual without prior notice.
CIRCUTOR S.A.U. on its web site, supplies its customers with the latest versions of the device specifi-
cations and the most updated manuals.
www.circutor.com
CIRCUTOR S.A.U. recommends using the original cables and accessories that are sup-
plied with the device.

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STM-S12, STM-S24, STM-H6, STM-H10, STM-H20
Instruction Manual
CONTENTS
SAFETY PRECAUTIONS .........................................................................................................................................................3
DISCLAIMER ..........................................................................................................................................................................3
CONTENTS.............................................................................................................................................................................4
REVISION LOG .......................................................................................................................................................................5
SYMBOLS...............................................................................................................................................................................5
1. VERIFICATION UPON RECEPTION....................................................................................................................................6
2. PRODUCT DESCRIPTION .................................................................................................................................................6
3. INSTALLATION OF THE DEVICE .......................................................................................................................................8
3.1.- PRELIMINARY RECOMMENDATIONS ........................................................................................................................8
3.2.- INSTALLATION .........................................................................................................................................................9
3.3.- DEVICE TERMINALS............................................................................................................................................... 10
3.3.1.- STM-S12 AND STM-S24 .................................................................................................................................. 10
3.3.2.- STM-H6............................................................................................................................................................11
3.3.3.- STM-H10......................................................................................................................................................... 12
3.3.4.- STM-H20......................................................................................................................................................... 13
3.4.- CONNECTION DIAGRAMS....................................................................................................................................... 14
3.4.1.- STM-S12 .......................................................................................................................................................... 14
3.4.2.- STM-S24 ......................................................................................................................................................... 15
3.4.3.- STM-H6........................................................................................................................................................... 16
3.4.4.- STM-H10 ......................................................................................................................................................... 17
3.4.5.- STM-H20 ........................................................................................................................................................ 18
4. OPERATION ................................................................................................................................................................... 19
4.1.- LEDs....................................................................................................................................................................... 19
4.2.- DIGITAL INPUTS..................................................................................................................................................... 19
4.3.- RTD TEMPERATURE PROBE INPUT .......................................................................................................................20
5. RS485 COMMUNICATIONS STMS12RS485 AND STMS24RS485 MODELS....................................................... 21
5.1.- CONNECTIONS ....................................................................................................................................................... 21
5.2.- MODBUS PROTOCOL..............................................................................................................................................22
5.3.- MODBUS COMMANDS ...........................................................................................................................................22
5.3.1.- MEASUREMENT VARIABLES...........................................................................................................................22
5.3.2.- MEMORY MAP IN BLOCKS ..............................................................................................................................25
5.3.3.- CONFIGURATION SETTINGS ...........................................................................................................................27
6. WIRELESS COMMUNICATIONS STMXXXFXXX MODELS ..........................................................................................29
6.1.- USAGE ENVIRONMENT AND HEALTH.....................................................................................................................29
6.2.- LoRaTM COMMUNICATIONS ....................................................................................................................................29
7. TECHNICAL FEATURES .................................................................................................................................................32
8. MAINTENANCE AND TECHNICAL SERVICE ..................................................................................................................38
9. GUARANTEE .................................................................................................................................................................38
10. EU DECLARATION OF CONFORMITY...........................................................................................................................39

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Instruction Manual
STM-S12, STM-S24, STM-H6, STM-H10, STM-H20
REVISION LOG
Table 1: Revision log.
Date Revision Description
11/21 M329B01-03-21A Initial release
Note: The images on the devices are for illustrative use only and may differ from the original device.
SYMBOLS
Table 2: Symbols.
Symbol Description
In accordance with the relevant European directive.
Device covered by European Directive 2012/19/EC. At the end of its useful life, do not leave the
device in a household refuse bin. Follow local regulations on electronic equipment recycling.
Direct current.
~Alternating current.

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STM-S12, STM-S24, STM-H6, STM-H10, STM-H20
Instruction Manual
1. VERIFICATION UPON RECEPTION
Upon receipt of the device, check the following points:
a) The device meets the specifications described in your order.
b) The device has not suffered any damage during transport.
c) Perform an external visual inspection of the device prior to switching it on.
d) Check that it has been delivered with the following:
- An installation guide.
If any problem is noticed upon reception, immediately contact the transport com-
pany and/or CIRCUTOR’s after-sales service.
2. PRODUCT DESCRIPTION
The STM is a monitoring device for photovoltaic farms, with up to 24 DC channels, a voltage channel
to measure up to 1500 V , 3 digital inputs, 1 Pt100 input and RS-485 or LoRa™communications.
The device can also be set up with wireless communications.
The current measurement is carried out through high linearity shunts, or through Hall effect trans-
formers.
The devices have:
- 4indicating LEDs.
- 3 digital inputs.
- 1 analogue input.
- 1input for an RTD temperature probe (Pt100).
- Wireless communications,to set up the device.
- RS-485 Communications (depending on model).
- LoRaTN Communications (depending on model).

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Instruction Manual
STM-S12, STM-S24, STM-H6, STM-H10, STM-H20
Table 3 specifies all the device models.
Table 3:List of models.
Model
Current measurement Communications
Shunt Hall effect No of
channels RS-485 LoRaTN (ISM Band)
868 MHz 915 MHz
STM-S12-485 - 12 - -
STM-S12-F868 - 12 - -
STM-S12-F915 - 12 - - 
STM-S24-485 - 24 - -
STM-S24-F868 - 24 - -
STM-S24-F915 - 24 - - 
STM-H6-F868 -6 - -
STM-H6-F915 -6 - - 
STM-H10-F868 -10 - -
STM-H10-F915 -10 - - 
STM-H20-F868 -20 - -
STM-SH20-F915 -20 - - 

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STM-S12, STM-S24, STM-H6, STM-H10, STM-H20
Instruction Manual
3. INSTALLATION OF THE DEVICE
3.1.- PRELIMINARY RECOMMENDATIONS
In order to use the device safely, personnel operating it must follow the safety meas-
ures that comply with the standards of the country where it is to be installed; operators
must wear the required personal protective equipment and they must heed the various
warnings indicated in this instruction manual.
The STM device must be installed by authorised, qualified personnel.
The power supply plug must be disconnected and measurement systems switched off before handling,
altering the connections or replacing the device. It is dangerous to handle the device while it is pow-
ered.
Cables must always be kept in perfect condition to avoid accidents or injury to personnel or installa-
tions.
Restrict the operation of the device to the specified measurement category, voltage or current values.
The manufacturer of the device is not responsible for any damage resulting from failure by the user
or installer to heed the warnings and/or recommendations set out in this manual, nor for damage
resulting from the use of non-original products or accessories or those made by other manufacturers.
Do not use the device to take any measurements if an anomaly or malfunction is detected.
Before carrying out maintenance, repair or handling of any of the device’s connections,
the device must be disconnected from all power sources, both from the device’s own
power supply and the measurement’s.
Contact the after-sales service if you notice that the device is not working properly.

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Instruction Manual
STM-S12, STM-S24, STM-H6, STM-H10, STM-H20
3.2.- INSTALLATION
The STM is a device that has specifically been designed to be installed inside an electric cabinet or
enclosed, with double insulation, fastened to a DIN rail.
Only the measurement circuit can be removed from the enclosure.
When the device is on, its terminals, opening covers or removing elements may ex-
pose the user to parts that are hazardous to touch. Do not use the device until it is
fully installed.
Under no circumstances should the device be installed or otherwise built into a
place where people may be directly exposed to it.
The STM devices have a Power LED to indicate that they are working, thereby
warning of the presence of voltage and current in the electronic circuit. Even if
the LED light is not on, the user is still responsible for verifying that the device is
disconnected from all power sources.
The device has a 24 V supply input. The power supply circuit must be connected using a cable
whose minimum cross-section is 1 mm2.
The STM’s power supply must be protected by fuses, a direct current magneto-ther-
mal circuit-breaker or any other means to prevent over-currents. These elements
must be sized according to the consumption of the device and the system voltage.

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STM-S12, STM-S24, STM-H6, STM-H10, STM-H20
Instruction Manual
3.3.- DEVICE TERMINALS
3.3.1.- STM-S12 AND STM-S24
17
18
19
20
22
23
24
25
27
28
29
30
45
44
43
42
40
39
38
37
35
34
33
32
46
41
36
21
26
31
1
2
3
456789
10
11
12
13
14
15
16
47 48 49
50
LED Estado/State
LED ED/DI 1
LED ED/DI 2 LED ED/DI 3
Figure 1: STM-S12 and STM-S24 terminals.
Table 4:List of terminals: STM-S12 and STM-S24.
Device terminals
1: 0, Power supply 26: Current output, channels 8 ... 5
2: Ground 27: CH4, Current input channel 4
3: +24V, Power supply 28: CH3, Current input channel 3
4: I3-, Digital input 3 29: CH2, Current input channel 2
5: I3+, Digital input 3 30: CH1, Current input channel 1
6: I2-, Digital input 2 31: Current output, channels 4 ... 1
7: I2+, Digital input 2 32: CH13, Current input channel 13(2)
8: I1-, Digital input 1 33: CH14, Current input channel 14(2)
9: I1+, Digital input 1 34: CH15, Current input channel 15(2)
10: A(+), Communications RS-485(1) 35: CH16, Current input channel 16(2)
11: S, Communications RS-485(1) 36: Current output, channels 13 ... 16
12: B(-), Communications RS-485(1) 37: CH17, Current input channel 17(2)
13: A(+), Communications RS-485(1) 38: CH18, Current input channel 18(2)
14: S, Communications RS-485(1) 39: CH19, Current input channel 19(2)
15: B(-), Communications RS-485(1) 40: CH20, Current input channel 20(2)
16:-Vpv, Voltage input 41: Current output, channels 17 ... 20
17: CH12, Current input channel 12 42: CH21, Current input channel 21(2)
18: CH11, Current input channel 11 43: CH22, Current input channel 22(2)
19: CH10, Current input channel 10 44: CH23, Current input channel 23(2)
20: CH9, Current input channel 9 45: CH24, Current input channel 24(2)
21: Current output, channels 12 ... 9 46: Current output, channels 21 ... 24
22: CH8, Current input channel 8 47: Pt100 probe input
23: CH7, Current input channel 7 48: Pt100 probe input
24: CH6, Current input channel 6 49: Pt100 probe input
25: CH5, Current input channel 5 50: LoRa™ antenna (3)
(1) Models STM-Sxx-485.
(2) Models STM-S24-xxxx.
(3) Models STM-Sxx-Fxxx.

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Instruction Manual
STM-S12, STM-S24, STM-H6, STM-H10, STM-H20
3.3.2.- STM-H6
17
16
15
14
13121110
9
8
21 20 19
18
LED Estado/State
LED ED/DI 1
LED ED/DI 2 LED ED/DI 3
654
3
21 7
Figure 2: STM-H6 terminals.
Table 5:List of terminals: STM-H6.
Device terminals
1: I L1, Current measurement Channel 1 12: I2-, Digital input 2
2: I L2, Current measurement Channel 2 13: I3+, Digital input 3
3: I L3, Current measurement Channel 3 14: I3-, Digital input 3
4: I L4, Current measurement Channel 4 15: +24V, Power supply
5: I L5, Current measurement Channel 5 16: Ground
6: I L6, Current measurement Channel 6 17: 0, Power supply
7: +Vpv, Voltage input 18: LoRa™ antenna
8:-Vpv, Voltage input 19: Pt100 probe input
9: I1+, Digital input 1 20: Pt100 probe input
10: I1-, Digital input 1 21: Pt100 probe input
11: I2+, Digital input 2

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STM-S12, STM-S24, STM-H6, STM-H10, STM-H20
Instruction Manual
3.3.3.- STM-H10
21
20
19
18
17
16
15
14
13
12
25 24 23
22
LED Estado/State
LED ED/DI 1
LED ED/DI 2 LED ED/DI 3
1086
4
2
1 3 5 7 9
11
Figure 3: STM-H10 terminals.
Table 6:List of terminals: STM-H10.
Device terminals
1: I L1, Current measurement Channel 1 14: I1-, Digital input 1
2: I L2, Current measurement Channel 2 15: I2+, Digital input 2
3: I L3, Current measurement Channel 3 16: I2-, Digital input 2
4: I L4, Current measurement Channel 4 17: I3+, Digital input 3
5: I L5, Current measurement Channel 5 18: I3-, Digital input 3
6: I L6, Current measurement Channel 6 19: +24V, Power supply
7: I L7, Current measurement Channel 7 20: Ground
8: I L8, Current measurement Channel 8 21: 0, Power supply
9: I L9, Current measurement Channel 9 22: LoRa™ antenna
10: I L10, Current measurement Channel 10 23: Pt100 probe input
11: +Vpv, Voltage input 24: Pt100 probe input
12:-Vpv, Voltage input 25: Pt100 probe input
13: I1+, Digital input 1

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Instruction Manual
STM-S12, STM-S24, STM-H6, STM-H10, STM-H20
3.3.4.- STM-H20
10198
17
6154132
11
112 3 14 5 16 7 18 9 20
21
31
30
29
28
27
26
25
24
23
22
35 34 33
32
LED Estado/State
LED ED/DI 1
LED ED/DI 2 LED ED/DI 3
Figure 4: STM-H20 terminals.
Table 7:List of terminals: STM-H20.
Device terminals
1: I L1, Current measurement Channel 1 19: I L19, Current measurement Channel 19
2: I L2, Current measurement Channel 2 20: I L20, Current measurement Channel 20
3: I L3, Current measurement Channel 3 21: +Vpv, Voltage input
4: I L4, Current measurement Channel 4 22:-Vpv, Voltage input
5: I L5, Current measurement Channel 5 23: I1+, Digital input 1
6: I L6, Current measurement Channel 6 24: I1-, Digital input 1
7: I L7, Current measurement Channel 7 25: I2+, Digital input 2
8: I L8, Current measurement Channel 8 26: I2-, Digital input 2
9: I L9, Current measurement Channel 9 27: I3+, Digital input 3
10: I L10, Current measurement Channel 10 28: I3-, Digital input 3
11: I L11, Current measurement Channel 11 29: +24V, Power supply
12: I L12, Current measurement Channel 12 30: Ground
13: I L13, Current measurement Channel 13 31: 0, Power supply
14: I L14, Current measurement Channel 14 32: LoRa™ antenna
15: I L15, Current measurement Channel 15 33: EPt100 probe input
16: I L16, Current measurement Channel 16 34: Pt100 probe input
17: I L17, Current measurement Channel 17 35: Pt100 probe input
18: I L18, Current measurement Channel 18

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STM-S12, STM-S24, STM-H6, STM-H10, STM-H20
Instruction Manual
3.4.- CONNECTION DIAGRAMS
3.4.1.- STM-S12
Canal / Channel 6
Alimentación Auxiliar
Power Supply
Media de Tensión
Voltage Measurement
+
-
Entrada de Corriente / Current input
Canal / Channel 1
Canal / Channel 2
Canal / Channel 3
Canal / Channel 4
Canal / Channel 5
Canal / Channel 7
Canal / Channel 8
Canal / Channel 9
Canal / Channel 10
Canal / Channel 11
Canal / Channel 12
Salida de Corriente / Output current
Canal / Channel 1 ... 4
Canal / Channel 5 ... 8
Canal / Channel 9 ... 12
Figure 5: Connection diagram STM-S12.

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Instruction Manual
STM-S12, STM-S24, STM-H6, STM-H10, STM-H20
3.4.2.- STM-S24
Canal / Channel 6
Alimentación Auxiliar
Power Supply
Media de Tensión
Voltage Measurement
+
-
Entrada de Corriente / Current input
Canal / Channel 1
Canal / Channel 13
Canal / Channel 2
Canal / Channel 14
Canal / Channel 3
Canal / Channel 15
Canal / Channel 4
Canal / Channel 16(
Canal / Channel 5
Canal / Channel 17
Canal / Channel 24
Canal / Channel 18
Canal / Channel 7
Canal / Channel 19
Canal / Channel 8
Canal / Channel 20
Canal / Channel 9
Canal / Channel 21
Canal / Channel 10
Canal / Channel 22
Canal / Channel 11
Canal / Channel 23
Canal / Channel 12
Salida de Corriente / Output current
Canal / Channel 1 ... 4
Canal / Channel 5 ... 8
Canal / Channel 9 ... 12
Canal / Channel 21 ... 24
Canal / Channel 17 ... 20
Canal / Channel 13 ... 16
Figure 6: Connection diagram STM-S24.

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STM-S12, STM-S24, STM-H6, STM-H10, STM-H20
Instruction Manual
3.4.3.- STM-H6
Canal / Channel 6
Alimentación Auxiliar
Power Supply
Media de Tensión
Voltage Measurement
+
-
Canal / Channel 1
Canal / Channel 2
Canal / Channel 3
Canal / Channel 4
Canal / Channel 5
Medida de Corriente / Current measurement
-
+
Figure 7: Connection diagram STM-H6.

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Instruction Manual
STM-S12, STM-S24, STM-H6, STM-H10, STM-H20
3.4.4.- STM-H10
Canal / Channel 10
Alimentación Auxiliar
Power Supply
Media de Tensión
Voltage Measurement
+
-
Canal / Channel 1
Canal / Channel 2
Canal / Channel 3
Canal / Channel 4
Canal / Channel 5
Medida de Corriente / Current measurement
Canal / Channel 8
Canal / Channel 6
Canal / Channel 7
Canal / Channel 9
-
+
Figure 8: Connection diagram STM-H10.

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STM-S12, STM-S24, STM-H6, STM-H10, STM-H20
Instruction Manual
3.4.5.- STM-H20
Canal / Channel 10
Alimentación Auxiliar
Power Supply
Media de Tensión
Voltage Measurement
+
-
Canal / Channel 1
Canal / Channel 2
Canal / Channel 3
Canal / Channel 4
Canal / Channel 5
Medida de Corriente / Current measurement
Canal / Channel 8
Canal / Channel 6
Canal / Channel 7
Canal / Channel 9
Canal / Channel 11
Canal / Channel 12
Canal / Channel 13
Canal / Channel 15
Canal / Channel 17
Canal / Channel 19
Canal / Channel 14
Canal / Channel 16
Canal / Channel 18
Canal / Channel 20
-
+
Figure 9: Connection diagram STM-H20.

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Instruction Manual
STM-S12, STM-S24, STM-H6, STM-H10, STM-H20
4. OPERATION
4.1.- LEDs
LED Estado/State
LED ED/DI 1
LED ED/DI 2 LED ED/DI 3
Figure 10: LEDs.
Table 8: LEDs.
LEDs Description
State
Red
On: Indicates that the device is powered and without errors.
Flashing slow: Indicates that the current is running in reverse through one
of the channels.
Flashing fast: Indicates an internal error in the device.
Digital input 1
Digital input 2
Digital input 3
Red
On: Indicates that the corresponding digital input is active.
4.2.- DIGITAL INPUTS
The devices have 3 voltage-free inputs and one common 24 V input to detect the logical state of the
external sensors (Terminals 4... 9 in Table 4,Terminals 9 ... 14 in Table 5, Terminals 13 ... 18 in Table 6 and
Terminals 23 ... 28 in Table 7).
The device captures the status of the inputs in real time (open contact or closed contact), and transmits
this information via LoRaTM or the RS-485 communication bus.
Note: The use and wiring of these inputs is completely optional, and doing so does not affect the op-
eration of the rest of the assembly.

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STM-S12, STM-S24, STM-H6, STM-H10, STM-H20
Instruction Manual
4.3.- RTD TEMPERATURE PROBE INPUT
The devices have an input for connecting a RTD temperature probe; specifically, a Pt100 probe can be
connected (Terminals 47 ... 49 in Table 4, Terminals 19 ... 21 in Table 5, Terminals 23 ... 25 in Table 6 and
Terminals 33 ... 35 in Table 7).