---
title: "Sfar MOD-1TE"
description: "Read RTD and thermocouple temperatures (Pt100/Pt500/Pt1000, NTC, J/K/T/N/S/R/B) via Modbus RTU. TapHome integration template for the Sfar MOD-1TE module."
url: "https://taphome.com/en/compatibility/sfar-mod-1te/"
language: en
lastmod: 2026-04-26
generator: hugo
ai:
  topics: ["modbus-rtu","sensor","rs485","din-rail","temperature-sensor","rtd","thermocouple"]
  questions: ["How to integrate the Sfar MOD-1TE temperature module with TapHome?","How to select the sensor type (Pt100, Pt500, Pt1000, NTC, thermocouple) on the MOD-1TE?","How to connect the Sfar MOD-1TE via RS-485 and a Modbus RTU-to-TCP gateway to TapHome?","What is the InputSettingsRegister parameter and which value should I use for my sensor?","How to change the default Modbus address, baud rate or parity on the Sfar MOD-1TE?","Why is my MOD-1TE temperature reading wrong or stuck — how do I troubleshoot?"]
---

# Sfar MOD-1TE

Communication: Modbus RTU

- [Aspar (SFAR) Official Website](https://www.aspar.com.pl)
- [MOD-1TE Product Page (Ampero)](https://ampero.eu/en/mini-series/32-mod-1te-1-temperature-input.html)

## Integration guide

The Sfar MOD-1TE is a single-channel temperature input module manufactured by **Aspar s.c.** (Chwaszczyno, Poland) and sold under the **SFAR** brand (Solutions for Automation and Robotics). It accepts Pt100, Pt500 and Pt1000 RTDs (in 2-wire or 3-wire configuration), Ni100, KTY81-110, NTC Carel and all common thermocouple types (J, K, T, N, S, R, B), and exposes the measured value on Modbus RTU at register 30053 (`A:51`) as °C × 10.

The module is RS-485 only, so an external **Modbus RTU-to-TCP gateway** (e.g. SFAR-S-ETH, USR-W630, Waveshare RS485-to-Ethernet) is required for TapHome — the template uses an `IpAddress` import parameter and reaches the module through that gateway.

## Hardware connection

### Module overview

The MOD-1TE is a 90 × 56 × 17 mm DIN-rail module (DIN EN 50022, IP40, -10 °C to +50 °C, PC/ABS housing). It carries one temperature input (TI), one digital alarm output (DO), an RS-485 port, a power input and a Mini USB type B configuration port on the front.

![Sfar MOD-1TE block diagram and front-panel LED indicators](https://taphome.com/images/compatibility/sfar-mod-1te/pcb-block-diagram_hu_6a6ccdd2020283a3.jpg)

| Indicator | Meaning |
|-----------|---------|
| **ON** | Module is correctly powered |
| **TX** | Module replied to a valid Modbus request |
| **IN** | A sensor is connected on the temperature input |
| **DO** | Digital output is active (alarm asserted) |

### Power supply

The module is powered through a 2-pin screw connector, accepting either DC or AC:

- **DC:** 10–38 V DC (typical 24 V DC, ~1 W consumption at 24 V)
- **AC:** 20–28 V AC (typical 24 V AC, ~2 VA at 24 V AC)

### RS-485 wiring

The RS-485 bus uses a 3-pin screw terminal — **A+**, **B-** and **GND** — and must be wired with a **shielded twisted pair** (A/B on the pair, GND on the third conductor or shield).

![Sfar MOD-1TE RS-485 communication and DC/AC power-supply wiring](https://taphome.com/images/compatibility/sfar-mod-1te/wiring-rs485-power_hu_f7b6836d13cdd146.jpg)

> [!WARNING]
> **Bus termination is mandatory.** Place a 120 Ω resistor across A/B at **both physical ends** of the RS-485 segment. Up to **128 modules** can share a single RS-485 segment.

> [!TIP]
> The RS-485, power supply and measuring inputs are galvanically isolated from each other (1 kV). For best EMC behaviour, ground the cable shield at one end only and keep RS-485 cabling away from contactors, motor drives and switching power supplies.

### Temperature input wiring

The temperature input uses a 3-pin screw terminal and supports several wiring schemes depending on the chosen sensor type. The *same* physical input is used for all sensor types — only the wiring and the `InputSettingsRegister` value change.

![Sfar MOD-1TE wiring diagrams for Pt100 2-wire, Pt100 3-wire and thermocouple measurement](https://taphome.com/images/compatibility/sfar-mod-1te/wiring-rtd-thermocouple_hu_9fff74cdbb4393ac.jpg)

- **RTD 2-wire (Pt100 / Pt500 / Pt1000):** Sensor on `INA` and `COM`, with a jumper between `INB` and `COM`. Lead-wire resistance must be compensated via register 40065.
- **RTD 3-wire (Pt100 / Pt500 / Pt1000):** Sensor connected with three conductors to `INA`, `INB` and `COM`. No lead-wire compensation needed — the third wire is used to cancel cable resistance.
- **Thermocouple (J / K / T / N / S / R / B):** Two-wire connection on `INA` (positive) and `INB` (negative). Cold-junction compensation is performed automatically inside the module.
- **NTC Carel:** Two-wire connection with a **7.5 kΩ ±1 % resistor in parallel** with the sensor.

### Digital alarm output (optional)

The module has one configurable digital output (250 mA / 50 V max), selectable as PNP or NPN, that can be used as a stand-alone thermostat output (cooling / heating with hysteresis). It is not exposed by the TapHome template — wiring it is optional.

![Sfar MOD-1TE digital output wiring (NPN and PNP variants)](https://taphome.com/images/compatibility/sfar-mod-1te/wiring-output_hu_21db7ecab228e4a9.jpg)

## Configuration

### Default Modbus settings

Out of the box, the MOD-1TE communicates with the following parameters (must be matched on the gateway / TapHome side):

| Parameter | Default value |
|-----------|---------------|
| Slave address | **1** |
| Baud rate | **19200** |
| Data bits | 8 |
| Parity | None |
| Stop bits | 1 |
| Modbus mode | RTU |
| Reply delay | 0 ms |

All of these are configurable — slave address 1–247 and baud rate up to 115200. Configuration is done over the front-panel **Mini USB type B** port using the free **Modbus Configurator** software ([download](https://www.aspar.com.pl/katalogi/IOMODULES/KONFIGURATOR/software/Konfigurator_IO.zip), no drivers required), or by writing the holding registers below over Modbus while the module is online:

| Register | Name | Values |
|----------|------|--------|
| 40003 | Baud rate | 0=2400, 1=4800, 2=9600, 3=19200 *(default)*, 4=38400, 5=57600, 6=115200 |
| 40004 | Stop bits / Data bits | LSB: 1=1 stop, 2=2 stops · MSB: 7=7 data, 8=8 data |
| 40005 | Parity | 0=none *(default)*, 1=odd, 2=even, 3=mark, 4=space |
| 40006 | Response delay | Time in ms |
| 40007 | Modbus mode | 0=RTU *(default)*, 1=ASCII |

> [!WARNING]
> Slave addresses must be **unique per RS-485 segment**. If two modules with the same address share a bus, both will reply at the same time and you will see CRC / framing errors on the gateway.

### Selecting the sensor type — `InputSettingsRegister`

The TapHome template's **`InputSettingsRegister`** import parameter is — despite the name — the **sensor-type code value** that gets written into manufacturer register **40061** ("Input settings") on init via:

```taphome
MODBUSWNE(H, 61, Int16, $[InputSettingsRegister])
```

Pick the value that matches the physical sensor wired on the temperature input:

| Code | Sensor type |
|------|-------------|
| 0 | Input disabled |
| 1 | Voltage 0–2048 mV |
| 2 | Voltage 0–256 mV |
| 3 | Thermocouple type **J** |
| 4 | Thermocouple type **K** |
| 5 | Thermocouple type **T** |
| 6 | Thermocouple type **N** |
| 7 | Thermocouple type **S** |
| 8 | Thermocouple type **R** |
| 9 | Thermocouple type **B** |
| 10 | **Pt100** 3-wire |
| 11 | **Pt100** 2-wire |
| 12 | Resistance 0–8 kΩ |
| 13 | **Ni100** |
| 14 | **KTY81-110** |
| 15 | **Pt500** 3-wire |
| 16 | **Pt500** 2-wire |
| 17 | **Pt1000** 3-wire |
| **18** | **Pt1000 2-wire** *(template default)* |
| 19 | **NTC Carel** (with 7.5 kΩ 1 % parallel resistor) |

Sensor measuring ranges (reference, from datasheet):

| Sensor | Operating range |
|--------|-----------------|
| Pt100 / Pt500 / Pt1000 | -200 °C … +850 °C |
| Ni100 | -60 °C … +180 °C |
| KTY81-110 | -55 °C … +150 °C |
| Type J thermocouple | -200 °C … +1200 °C |
| Type K thermocouple | -200 °C … +1300 °C |
| Type T thermocouple | -200 °C … +400 °C |
| Type N thermocouple | -200 °C … +1300 °C |
| Type S / R thermocouple | 0 °C … +1700 °C |
| Type B thermocouple | 0 °C … +1800 °C |
| Resolution / accuracy | 0.1 °C / ±0.5 °C |

> [!TIP]
> For voltage (codes 1–2) and resistance (code 12) modes the same register 30053 is read but with different scaling (mV × 10 / mV × 100 / Ω). The TapHome template assumes a *temperature* sensor (°C × 10) and applies the `/10` formula automatically — using a non-temperature sensor type is out of scope for this template.

### Enabling Modbus communication via the gateway

Because the MOD-1TE has no native Ethernet, the module is reached through an external Modbus RTU-to-TCP gateway. Typical setup:

1. Wire the module's **A+ / B- / GND** to the gateway's RS-485 port. Add a 120 Ω termination resistor at the far end of the bus.
2. Power the gateway and the MOD-1TE.
3. In the gateway's web interface, set the serial side to match the module: **19200 baud, 8 data bits, no parity, 1 stop bit, RTU mode**. Disable any "modbus poll / address translation" features — TapHome talks raw Modbus TCP.
4. Set a **static IP** for the gateway (or DHCP reservation on the router) so TapHome can reach it reliably.
5. In TapHome service settings, import the `Sfar MOD-1TE` template and fill in:
   - **IpAddress** — IP of the gateway
   - **SlaveId** — Modbus address of the module (default `1`)
   - **InputSettingsRegister** — sensor-type code from the table above (default `18` = Pt1000 2-wire)

### Module variables

| Variable | Default | Description |
|----------|---------|-------------|
| `IpAddress` | `192.168.0.1` | IPv4 address of the Modbus RTU-to-TCP gateway. |
| `SlaveId` | `1` | Modbus slave address of the module on the RS-485 segment (1–247). Must be unique per segment. |
| `InputSettingsRegister` | `18` | Sensor-type code written to register 40061 on init. **Despite the name, this is a value, not a register address.** Use the table above to pick the correct code for your physical sensor. |

## Device capabilities

### Temperature reading

The template exposes a single device — **Temperature Sensor** — that reads register `A:51` (manufacturer register 30053, "Temperature") as a signed 16-bit integer and divides by 10 to obtain the value in °C. The sensor type is configured at install time through the `InputSettingsRegister` parameter (default `18` = Pt1000 2-wire), and the module then handles RTD linearisation, lead compensation (3-wire), thermocouple linearisation and cold-junction compensation internally.

```text
ReadTemperature: MODBUSR(A, 51, Int16) / 10
```

> [!TIP]
> Because every MOD-1TE template instance covers exactly one sensor, install one TapHome module per physical MOD-1TE on the bus and set `SlaveId` accordingly (e.g. 1, 2, 3 …). All modules can share a single RS-485 segment and a single RTU-to-TCP gateway.

## Troubleshooting

### No temperature value (device offline in TapHome)

1. Check the **ON** LED on the module — if it is off, verify the 24 V DC / 24 V AC supply on the power terminal.
2. Check the **TX** LED while TapHome is polling — it should blink on every successful request. If TX never lights up:
   - Verify `IpAddress` matches the gateway and that the gateway is reachable (ping).
   - Verify the gateway's serial settings: **19200 / 8N1 / RTU**.
   - Verify `SlaveId` matches the address actually configured on the module (default `1`).
   - Swap A and B — many gateways label them in reverse.
   - Check that GND is connected between the module and the gateway. Without GND, the receiver bias may sit outside the valid common-mode range.
3. Verify there is exactly **one 120 Ω termination resistor at each end** of the RS-485 segment — neither more nor fewer.

### Reading is stuck at 0, -200 °C or some extreme value

1. Check the **IN** LED — if it is off, the sensor is not detected on the input. Inspect the wiring on the temperature input terminal:
   - RTD 2-wire: jumper between INB and COM is required.
   - RTD 3-wire: all three conductors must be in place.
   - Thermocouple: polarity matters (positive on INA, negative on INB).
   - NTC Carel: 7.5 kΩ ±1 % parallel resistor must be present.
2. Verify `InputSettingsRegister` matches the physical sensor — a Pt100 wired but the parameter set to `18` (Pt1000 2-wire) will produce wildly wrong values.
3. For 2-wire RTDs over long cable runs, configure lead-wire resistance compensation in register 40065 using the Modbus Configurator (or accept the offset).

### Two modules respond at the same time / random CRC errors

Two devices share the same `SlaveId` on the RS-485 segment. Disconnect modules one by one and use the Modbus Configurator over Mini USB to set unique addresses (1–247).

### Changing baud rate or parity

If you changed baud rate / parity via register 40003 / 40005 over Modbus and lost communication afterwards, connect the **Mini USB** port to a PC and use the Modbus Configurator — it talks to the module directly over USB and is independent of the RS-485 settings, so you can read back and reset the values.

### Identifying the module / firmware

Register **30001** encodes the firmware (high byte ÷ 10) and the module type code (low byte). For MOD-1TE the type code is **41** (`0x29`). Reading 30001 over Modbus is a quick sanity check that the gateway, slave ID and serial settings are all correct before TapHome is configured.

## Available devices 1

These devices appear in TapHome after import.

Sfar MOD-1TE Module

Custom Variables

|                                        |                                                                                                                                                                                                                                                                                                                                                                         |
|----------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `InputSettingsRegister` (integer) = 18 | Sensor-type code written into manufacturer register 40061 on init. Despite the name, this is a sensor-type VALUE, not a register address. Allowed values: 0=disabled, 1–2=voltage, 3–9=thermocouples J/K/T/N/S/R/B, 10/11=Pt100 3-wire/2-wire, 12=resistance, 13=Ni100, 14=KTY81-110, 15/16=Pt500 3-wire/2-wire, 17/18=Pt1000 3-wire/2-wire (default 18), 19=NTC Carel. |

Temperature Sensor Temperature Sensor Read-only

Measured temperature in °C — reads register 30053 (A:51, Int16) and divides by 10. Sensor type (Pt100, Pt500, Pt1000, Ni100, KTY81-110, NTC Carel or thermocouple J/K/T/N/S/R/B) is selected at install time via the InputSettingsRegister parameter (default 18 = Pt1000 2-wire).

Register: A:51 Int16 Unit: °C numeric

Read temperature

```taphome
MODBUSR(A, 51, Int16)/10
```

Initialize

```taphome
MODBUSWNE(H, 61, Int16, $[InputSettingsRegister])
```

**Connection:** Modbus RTU • 19200 baud• 8N1 • Slave ID: $\[SlaveId]

Possible improvements (14)

- 30001 Version / Type ID — R, 16-bit. High byte = firmware × 10; low byte = module type code (MOD-1TE = 41). Useful for diagnostics / module identification
- 30002 Slave Address (read-back) — R, 16-bit. Read-only mirror of the configured Modbus slave address
- 30051 Inputs Bitfield — R, bitfield. Bit high = sensor connected on the corresponding input. Useful for sensor-presence detection / wiring diagnostics
- 30054 Junction Temperature (cold-junction reference) — R, Int16, °C × 10. Cold-junction compensation reference temperature — relevant only for thermocouple measurements
- 40003 Baud Rate — R/W, 0–6 (0=2400, 1=4800, 2=9600, 3=19200, 4=38400, 5=57600, 6=115200). Configurable from Modbus Configurator over Mini USB
- 40005 Parity — R/W, 0–4 (None / Even / Odd / etc.). Default None. Configurable from Modbus Configurator
- 40010 Analog Filter — R/W, 1–10. Smoothing coefficient for the analog input — higher value = stronger averaging, slower response
- 40052 Outputs / Alarm Bit — R/W, bitfield. Bit reflects the digital output (alarm) state. Module has a built-in PNP/NPN digital output (250 mA / 50 V max) that can be driven by alarm logic
- 40056 MAX Alarm Level — R/W, Int16, °C × 10. Upper temperature alarm threshold — triggers digital output when measurement exceeds this value
- 40057 MIN Alarm Level — R/W, Int16, °C × 10. Lower temperature alarm threshold — triggers digital output when measurement falls below this value
- 40062 Output Settings — R/W. Configures digital-output behaviour: +256 = cooling (energise on temperature ABOVE setpoint), +512 = heating (energise on temperature BELOW setpoint). Combined with alarm levels for thermostat-style control
- 40063 Alarm Value — R/W, Int16, °C × 10. Alarm setpoint used together with Output Settings (cooling/heating) and Alarm Hysteresis
- 40064 Alarm Hysteresis — R/W, Int16, °C × 10. Hysteresis band around the alarm setpoint to prevent output chattering
- 40065 Lead-Wire Resistance Compensation — R/W. Cable resistance compensation for 2-wire RTD connections (Pt100/Pt500/Pt1000 2-wire). Allows manual entry of lead-wire resistance to subtract from the measurement. Not needed for 3-wire RTD wiring

## Import parameters

Enter these values when you import the XML.

| Asked in the app      | Default       |
|-----------------------|---------------|
| InputSettingsRegister | `18`          |
| Slave ID              | `1`           |
| IP address            | `192.168.0.1` |

## Sources

- Aspar Mini Modbus 1TE — User Manual (EN, v1.8)
  
  [www.aspar.com.pl](https://www.aspar.com.pl/katalogi/IOMODULES/1TE_en.pdf) 2026-04-26
  
  [PDF](https://taphome.com/compatibility/devices/sfar-mod-1te/manufacturer/1TE_en.pdf)
- MOD-1TE — Ampero (Aspar s.c.) product page
  
  [ampero.eu](https://ampero.eu/en/mini-series/32-mod-1te-1-temperature-input.html) 2026-04-26
- ASPAR SFAR Mini Modbus 1TE — ManualsLib register table
  
  [www.manualslib.com](https://www.manualslib.com/manual/1629979/Aspar-Sfar-Mini-Modbus-1te.html) 2026-04-26

Manufacturer documents are © their respective owners. They are provided as published by the manufacturer, for reference only.

## Related Documentation

- [Modbus Integration](https://taphome.com/en/compatibility/modbus-guide/)
- [Modbus](https://taphome.com/en/docs/integration/modbus/)
- [Simple configuration using templates](https://taphome.com/en/docs/integration/modbus/templates/)
- [Modbus scripts and prefetch](https://taphome.com/en/docs/script/modbus-scripts/)
- [Modbus functions](https://taphome.com/en/docs/script/modbus/)
- [Modbus data types](https://taphome.com/en/docs/script/modbus-data-types/)