Chapter 1 Overview
NCS-TT108 Smart Temperature Transmitter uses fieldbus technology and is a new generation of smart fieldbus temperature transmitter. It is an indispensable field device for process control. The transmitter integrates abundant function blocks and realizes both general measurement functions and complex control strategies.
NCS-TT108 supports eight-channel temperature sensor input. It is compatible with a variety of RTD and thermocouple sensors and has a wide measuring range. Each channel can be individually configured for sensor type and 2-wire or 3-wire RTD connection. The eight channels are divided into four temperature acquisition modules with security isolation between modules. Each module has two temperature input channels.
The transmitter adopts a PVC fire-retardant plastic shell suitable for control room installation. For outdoor installation, an outdoor aluminum box with waterproof body and die-cast aluminum materials must be selected.
NCS-TT108 uses digital technology and provides a simple interface between the field and the control room, reducing installation, operation and maintenance costs. It supports FF and PA protocols and is widely used in petroleum, chemical, power and metallurgical industries.
Chapter 2 Installation
2.1 Mount of Transmitter
- Guide rail mounting
- Screw mounting
When outdoor installation is required, the transmitter must be mounted in an outdoor box made of die-casting aluminum with copper-chromed cable sealing points.
2.2 Connection
Power and bus signal share one pair of cables (bus cable). It is recommended to use IEC 61158-2 compliant fieldbus cable.
- Bus terminals (from left to right): Bus+, Bus–, Earth
- Sensor terminals: Every three terminals form one channel (Channel 1 to Channel 8 from left to right)
Signal and bus cables should not share conduits or open wire trunking with high-power equipment and should be kept away from high-power devices.
Outdoor box has nine cable sealing connectors: one for Power/Signal and eight for sensor channels.
Chapter 3 Working Principle and Structure
NCS-TT108 collects RTD and thermocouple signals, converts them into fieldbus signals after arithmetic processing, and achieves temperature measurement.
Main components:
- Communication board – Core component providing fieldbus communication, control, diagnosis and maintenance.
- Instrument board – Connects 8-channel temperature inputs, converts sensor signals to digital signals, performs temperature calculation, and communicates with the communication board via isolation interface.
3.2 Dimensions
3.3 Structure
Chapter 4 Configuration
4.1 Topology Connection
Supports multiple FF network topologies. Maximum bus length is 1900 m (extendable to 10 km with repeaters). Terminal matching resistors are required at both ends of the bus.
4.2 Function Block
| Function Block | Descrição |
|---|---|
| Resource | Device identity (name, manufacturer, serial number) |
| Sensor Transducer | Reads physical channel data and processes according to sensor type |
| Differential Transducer | Calculates difference between any two physical channels |
| AI | Analog input with range conversion, square root, etc. |
| MAI | Multi-channel analog input |
| ISEL | Input selection (max, min, medium, etc.) |
4.3 Transducer Block Configuration
Supported software: Microcyber FF Configuration Software, NCS4000, NI-FBUS Configurator, DeltaV, etc.
Key operations:
- Sensor type configuration (SENSOR_TYPE)
- 2-wire zero point calibration (TWO_WIRES_COMPENSATION)
- Cold junction compensation (BODY_TEMP_COMPENSATION)
- 2-point linearization calibration (CAL_POINT_HI / CAL_POINT_LO)
- Differential transducer block configuration (INPUT_A, INPUT_B, DIFFERENTIAL_TYPE)
4.6 Configuration Setting and Indicating
Two DIP switches:
- Simulate Enable – ON to enable simulation function
- Write Lock – ON to prevent any write operations
Ten indicator lights show bus power status, communication status and the working status of eight temperature input channels.
Chapter 5 Maintenance
| Phenomenon | Solução |
|---|---|
| No Communication | Check bus cable connection, power polarity, shield grounding (single-point); verify bus power (9–32 V) and noise limits; check network topology, terminators and address conflict; replace module if necessary |
| Reading Error | Check sensor short/open/ground; adjust damping; check housing grounding and terminal moisture; keep cables away from strong EMI; verify sensor type and function block parameters |
Chapter 6 Technical Specifications
6.1 Basic Parameters
| Item | Especificação |
|---|---|
| Sinal de Entrada | RTD: Pt100, Cu50, Cu100, 0–500 Ω, 0–4000 Ω; Thermocouple: B, E, J, N, K, R, S, T; Voltage: –100 mV ~ 100 mV |
| Channel | 8-channel |
| RTD Wiring | 2-wire, 3-wire |
| Bus Power | 9–32 VDC; Current consumption (static) ≤ 20 mA |
| Isolamento | Between input channel and bus: 500 Vrms; Between temperature modules: 500 Vrms |
| Working Temperature | –40 °C ~ 85 °C |
| Umidade | 0% ~ 100% RH |
| Start Time | ≤ 5 s |
| Tempo de Atualização | 0,2 s |
| Proteção | IP20; Outdoor box IP67 |
6.2 RTD Technical Parameters (25 °C)
| Sensor | Suggested Range | Precisão |
|---|---|---|
| 0–500 Ω / 0–4000 Ω | — | ±0.05% |
| Pt100 | –200 ~ 850 °C | ±0.2 °C |
| Pt1000 | –200 ~ 850 °C | ±0.1 °C |
| Cu50 | –50 ~ 150 °C | ±0.3 °C |
| Cu100 | –50 ~ 150 °C | ±0.2 °C |
6.3 Thermocouple Parameters (25 °C)
| Digitar | Suggested Range | Precisão |
|---|---|---|
| mV | –100 ~ 100 mV | 0.05% |
| B | 500 ~ 1810 °C | ±1.0 °C |
| E | –200 ~ 1000 °C | ±0.6 °C |
| J | –190 ~ 1300 °C | ±0.8 °C |
| K | –200 ~ 1372 °C | ±0.8 °C |
| N | –190 ~ 1300 °C | ±1.0 °C |
| R | 0 ~ 1768 °C | ±1.0 °C |
| S | 0 ~ 1768 °C | ±1.0 °C |
| T | –200 ~ 400 °C | ±0.6 °C |
Cold-junction compensation accuracy: < ±1 °C
6.4 Physical Parameters
- Material: Flame-retardant plastic; Die-casting aluminum (outdoor box)
- Protection: IP20; Outdoor box IP67
- Weight: 0.42 kg; 1.98 kg (with outdoor box)
6.5 Model Reference
- F: FF-H1 Protocol
- W: Selective Outdoor Box
