SIMENS Transmitter SITRANS TW, four-wire technology, Universal, HART

SITRANS TW

SITRANS TW is a consistent further development of the hundred thousand times proven SITRANS T for the 4wire system in the mounting rail housing. Its many new functions set new standards in temperature transmitters. Its diagnostic and simulation functions provide the necessary clarity during commissioning and operation. Its HART®-interface makes the SITRANS TW easily adaptable to any measuring job with SIMATIC PDM.

Physical values can be preset with the simulation function. This enables testing of the complete signal path right as far as the control system without the need for tools. The drag pointer functions measure the system’s process variable minimum and maximum.

All SITRANS TW control room devices are available in non-intrinsically safe versions and intrinsically safe versions for applications under extreme conditions.

The user-friendly transmitters for the control room

The SITRANS TW universal transmitter is a further development of the service-proven SITRANS T for the 4-wire system in a mounting rail housing. With numerous new functions it sets new standards for temperature transmitters.

With its diagnostics and simulation functions the SITRANS TW provides the necessary insight during commissioning and operation. And using its HART interface the SITRANS TW can be conveniently adapted with SIMATIC PDM to every measurement task.

All SITRANS TW control room devices are available in a non-intrinsically safe version as well as in an intrinsically safe version for use with the most stringent requirements.

Product No. / Product DescriptionListprice / Your price
7NG3242-…..
SITRANS TW universal transmitter for rail mounting in four-wire system

Benefits

  • Explosion protection [EEx ia] or [EEx ib] for measurements with sensors in the hazardous area
  • Temperature-linear characteristic for all temperature sensors
  • Temperature-linear characteristic can be selected for all temperature
    sensors
  • Diagnostic functions
  • Slave pointer functions

Application

The SITRANS TW transmitter is a four-wire rail-mounted device with a universal input circuit for connection to the following sensors and signal sources:

  • Resistance thermometer
  • Thermocouples
  • Resistance-based sensors/potentiometers
  • mV sensors
  • As special version:
    • V sources
    • Current sources

The 4-wire rail-mounted SITRANS TW transmitter wire is designed for control room installation. It must not be mounted in potentially explosive atmospheres.

All SITRANS TW control room devices are available in a non-intrinsically safe version as well as in an intrinsically safe version for use with the most stringent requirements.

Integration

System configuration

Possible system configurations

The SITRANS TW transmitter as a four-wire rail-mounted device can be used in a number of system configurations: as a stand-alone version or as part of a complex system environment, e.g. with SIMATIC S7. All device functions are available via HART communication.

Communication options through the HART interface:

  • HART communicator
  • HART modem connected to PC/laptop on which the appropriate software is available, e.g. SIMATIC PDM
  • HART-compatible control system (e.g. SIMATIC S7‑400 with ET 200M)

Dimensional drawings

Dimensions for control room mounting, rail mounting in mm (inches)

Function

Features
  • Transmitter in four-wire system with HART interface
  • Housing can be mounted on 35 mm rail or 32 mm G rail
  • Screw plug connector
  • All circuits electrically isolated
  • Output signal: 0/4 to 20 mA or 0/2 to 10 V
  • Power supplies: 115/230 V AC/DC or 24 V AC/DC
  • Explosion protection [EEx ia] or [EEx ib] for measurements with sensors in the hazardous area
  • Temperature-linear characteristic for all temperature sensors
  • Temperature-linear characteristic can be selected for all temperature sensors
  • Automatic correction of zero and span
  • Monitoring of sensor and cable for open-circuit and short- circuit
  • Sensor fault and/or limit can be output via an optional sensor fault/limit monitor
  • Hardware write protection for HART communication
  • Diagnostic functions
  • Slave pointer functions
  • SIL 1
Mode of operation

The signal output by a resistance-based sensor (two-wire, three-wire, four-wire system), voltage source, current source or thermocouple is converted by the analog-to-digital converter (1, function diagram) into a digital signal. This is evaluated in the microcontroller (2), corrected according to the sensor characteristic, and converted by the digital-to-analog converter (6) into an output current (0/4 to 20 mA) or output voltage (0/2 to 10 V). The sensor characteristics as well as the electronics data and the data for the transmitter parameters are stored in the non-volatile memory (3).

AC or DC voltages can be used as the power supply (13). Any terminal connections are possible for the power supply as a result of the bridge rectifier in the power supply unit. The PE conductor is required for safety reasons.

A HART modem or a HART communicator permit parameterization of the transmitter using a protocol according to the HART specification. The transmitter can be directly parameterized at the point of measurement via the HART output terminals (10).

The operation indicator (4) identifies a fault-free or faulty operating state of the transmitter. The limit monitor (9) enables the signaling of sensor faults and/or limit violations. In the case of a current output, the current can be checked on a meter connected to test socket (12).

Diagnosis and simulation functions

The SITRANS TW comes with extensive diagnosis and simulation functions.

Physical values can be defined with the simulation function. It is thus possible to check the complete signal path from the sensor input to inside the control system without additional equipment. The slave pointer functions are used to record the minimum and maximum of the plant’s process variable.

Dimensional drawings

Dimensions for control room mounting, rail mounting in mm (inches)

Technical specifications

Input

Selectable filters to suppress the line frequency

50 Hz, 60 Hz, also 10 Hz for special applications (line frequency filter is similar with measuring frequency)

Resistance thermometer

Measured variable

Temperature

Measuring range

Assignable

Span

Min. 25 °C (45 °F) x 1/scaling factor

Sensor type

  • Acc. to IEC 751

Pt100 (IEC 751)

  • Acc. to JIS C 1604-81

Pt100 (JIS C1604-81)

  • Acc. to DIN 43760

Ni100 (DIN 43760)

  • Special type (RRTD ≤ 500 Ω)

Multiples or fractions of the specified basic values can be assigned (e.g. Pt500, Ni120)

Characteristic curve

Temperature-linear, resistance-linear or customer-specific

Type of connection

  • Normal connection
  • Sum or parallel connection
  • Mean-value or differential connection

Connection

2, 3 or 4-wire system

Measuring range limits

Depending on type of connected thermometer (defined range of resistance thermometer)

Sensor breakage monitoring

Monitoring of all connections for wire break (function can be switched off)

Sensor short-circuit monitoring

Configurable response threshold (function can be switched off)

Resistance-based sensor, potentiometer

Measured variable

Actual resistance

Measuring range

Assignable

Span

Min. 10 Ω

Characteristic curve

Resistance-linear or customer-specific

Type of connection

  • Normal connection
  • Differential connection
  • Mean-value connection

Connection

2, 3 or 4-wire system

Input range

0 … 6000 Ω;

with mean-value and difference circuits: 0 … 3000 Ω

Sensor breakage monitoring

Monitoring of all connections for wire break (function can be switched off)

Sensor short-circuit monitoring

Configurable response threshold (function can be switched off)

Thermocouples

Measured variable

Temperature

Measuring range

Assignable

Span

Min. 50 ℃ (90 °F) x 1/scaling factor

Measuring range limits

Depending on type of thermocouple element

Thermocouple element

  • Type B

Pt30 %Rh/Pt6 %Rh (DIN IEC 584)

  • Type C

W5%-Re (ASTM 988)

  • Type D

W3%-Re (ASTM 988)

  • Type E

NiCr/CuNi (DIN IEC 584)

  • Type J

Fe/CuNi (DIN IEC 584)

  • Type K

NiCr/Ni (DIN IEC 584)

  • Type L

Fe-CuNi (DIN 43710)

  • Type N

NiCrSi-NiSi (DIN IEC 584)

  • Type R

Pt13 %Rh/Pt (DIN IEC 584)

  • Type S

Pt10 %Rh/Pt (DIN IEC 584)

  • Type T

Cu/CuNi (DIN IEC 584)

  • Type U

Cu/CuNi (DIN 43710)

Special type (-10 mV ≤ UTC ≤ 100 mV)

Characteristic curve

Temperature-linear, voltage-linear or customer-specific

Type of connection

  • Normal connection
  • Averaging connection
  • Mean-value connection
  • Differential connection

Reference junction compensation

None, device-internal measurement, external measurement or predefined fixed value

Sensor breakage monitoring

Function can be switched off

mV sensors

Measured variable

DC voltage

Measuring range

Assignable

Span

Min. 4 mV

Input range

-120 … +1000 mV

Characteristic curve

Voltage-linear or customer-specific

Overload capacity of inputs

Max. ± 3.5 V

Input resistance

≥ 1 MΩ

Sensor current

Approx. 180 μA

Sensor breakage monitoring

Function can be switched off

V sources

Measured variable

DC voltage

Measuring range

Assignable

Characteristic curve

Voltage-linear or customer-specific

Input range/min. Span

  • Devices with 7NG3242-xxxx1 or 7NG3242-xxxx0 with U/I plug

-1.2 … + 10 V/0.04 V

  • Devices with 7NG3242-xxxx2

-12 … +100 V/0.4 V

  • Devices with 7NG3242-xxxx3

-120 V … +140 V/4.0 V

Sensor breakage monitoring

Not possible

μA-, mA sources

Measured variable

DC voltage

Measuring range

Assignable

Characteristic curve

Current-linear or customer-specific

Input range/min. Span

  • Devices with 7NG3242-xxxx4

-12 μA … +100 μA/0.4 μA

  • Devices with 7NG3242-xxxx5

-120 μA … +1000 μA/4 μA

  • Devices with 7NG3242-xxxx6

-1.2 mA … +10 mA/0.04 mA

  • Devices with 7NG3242-xxxx7 or 7NG3242-xxxx0 with U/I plug

-12 mA … +100 mA/0.4 mA

  • Devices with 7NG3242-xxxx8

-120 mA … +1000 mA/4 mA

Sensor breakage monitoring

Not possible

Output

Output signal

Load-independent direct current 0/4 … 20 mA, can be switched to load-independent DC voltage 0/2 … 10 V using plug-in jumpers

Current 0/4 … 20 mA

  • Overrange

-0.5 … +23.0 mA, infinitely adjustable

  • Output range following sensor fault (conforming to NE43)

-0.5 … +23.0 mA, infinitely adjustable

  • Load

≤ 650 Ω

  • No-load voltage

≤ 30 V

Voltage 0/2 … 10 V

  • Overrange

-0.25 … +10.75 V, infinitely adjustable

  • Output range following sensor fault

-0.25 … +10.75 V, infinitely adjustable

  • Load resistance

≥ 1 kΩ

  • Load capacitance

≤ 10 nF

  • Short-circuit current

≤ 100 mA (not permanently short-circuit-proof)

  • Electrical damping
  • adjustable time constant T63

0 … 100 s, in steps of 0.1 s

  • Current source/voltage source

Infinitely adjustable within the entire operating range

Sensor fault/limit signaling

By operation indicator, relay output or HART interface

Operation indicator

Flashing signal

  • Limit violation

Flashing frequency 5 Hz

  • Sensor fault

Flashing frequency 1 Hz

Relay outputs

Either as NO or NC contact with 1 changeover contact

  • Switching capacity

≤ 150 W, ≤ 625 VA

  • Switching voltage

≤ 125 V DC, ≤ 250 V AC

  • Switching current

≤  2.5 A DC

Sensor fault

Signalling of sensor or line breakage and sensor short-circuit

Limit monitoring

  • Operating delay

0 … 10 s

  • Monitoring functions of limit module
  • Sensor fault (breakage and/or short-circuit)
  • Lower and upper limit
  • Window (combination of lower and upper limits)
  • Limit and sensor fault detection can be combined
  • Hysteresis

Configurable between 0 and 100 % of measuring range

Auxiliary power

Universal power supply unit

115/230 V AC/DC or 24 V AC/DC

Tolerance range for power supply

  • With 115/230 V AC/DC PSU

80 … 300 V DC; 90 … 250 V AC

  • With 24 V AC/DC PSU

18 … 80 V DC; 20.4 … 55.2 V AC (in each case interruption-resistant up to 20 ms in the complete tolerance range)

Tolerance range for mains frequency

47 … 63 Hz

Power consumption with

  • 230 V AC

≤ 5 VA

  • 230 V DC

≤ 5 W

  • 24 V AC

≤ 5 VA

  • 24 V DC

≤ 5 W

Electrical isolation

Electrically isolated circuits

Input, output, power supply and sensor fault/limit monitoring output are electrically isolated from one another. The HART interface is electrically connected to the output.

Working voltage between all electrically isolated circuits

The voltage Urms between any two terminals must not exceed 300 V

Measuring accuracy

Accuracy

  • Error in the internal reference junction

≤ 3 °C ± 0.1 °C / 10 °C (≤ 5.4 °F ± 0.18  °F / 18 °F)

  • Error of external reference junction terminal 7NG3092-8AV

≤ 0.5 °C ± 0.1 °C / 10 °C (≤ 0.9 °F ± 0.18 °F / 18 °F)

  • Digital output

See “Digital error”

  • Analog output IAN or UAN

≤ 0.05 % of meas. span plus digital error

Influencing effects (referred to the digital output)

Compared to the max. measuring span:

  • Temperature drift

≤ 0.08 % / 10 °C (≤ 0.08 % / 18 °F)

≤ 0.2 % in the range -10 … +60 °C (14 … 140 °F)

  • Long-term drift

≤ 0.1 % / year

Influencing effects referred to the analog output IAN or UAN

Compared to the measuring span:

  • Temperature drift

≤ 0.08 % / 10°C (≤ 0.08 % / 18 °F)

≤ 0.2 % in the range -10 … +60 °C (14 … 140 °F)

  • Power supply

≤ 0.05 % / 10 V

  • Load with current output

≤ 0.05 % on change from 50 Ω to 650 Ω

  • Load with voltage output

≤ 0.1 % on change in the load current from 0 mA to 10 mA

  • Long-term drift (start-of-scale value, measuring span)

≤ 0.03 % / month

Response time (T63 without electrical damping)

≤ 0.2 s

Insulation tests

Auxiliary power relative to input and output

3.54 kV DC; 2 s

Input relative to output and limit monitor

2.13 kV DC; 2 s

Output relative to limit monitor

2.13 kV DC; 2 s

PE/ground conductor relative to auxiliary power, input, output, and limit monitor

0.71 kV AC; 2 s

Electromagnetic compatibility

According to EN 61326 and NAMUR NE21

Certificates and approvals

Intrinsic safety

  • for 7NG3242-xAxxx

II (1) G [Ex ia Ga] IIC

  • for 7NG3242-xBxxx

II (1) D [Ex ia Da] IIIC

EC type-examination certificate

TÜV (German Technical Inspectorate) 01 ATEX 1675

Other certificates

EAC Ex (GOST)

Conditions of use

Installation conditions

Location (for devices with explosion protection)

  • Transmitters

Outside the hazardous area

  • Sensor

Within hazardous area Zone 1 (also in Zone 0 in conjunction with the prescribed protection requirements for the sensor)

Ambient conditions

Ambient temperature

-25 … +70 °C (-13 … +158 °F)

Storage temperature

-40 … +85 °C (-40 … +185 °F)

Climatic class

  • Relative humidity

5 … 95 %, no condensation

Design

Weight

Approx. 0.24 kg (0.53 lb)

Enclosure material

PBT, glass-fibre reinforced

Degree of protection according to IEC 529

IP20

Degree of protection according to VDE 0100

Protection class I

Type of installation

35-mm DIN rail (1.38 inch) (EN 50022) or 32-mm G-type rail (1.26 inch) (EN 50035)

Electrical connection / process connection

Screw plug connectors, max. 2.5 mm² (0.01 inch²)

Parameterization interface

Protocol

HART, version 5.9

Load with connection of

  • HART communicator

230 … 650 Ω

  • HART modem

230 … 500 Ω

Software for PC/laptop

SIMATIC PDM version V5.1 and later

Digital error

Resistance thermometer

Input

Measuring range

Max. permissible line resistance

Digital error

°C / (°F)

Ω

°C / (°F)

IEC 751

  • Pt10

-200 … +850
(-328 … +1562)

20

3.0 (5.4)

  • Pt50

-200 … +850
(-328 … +1562)

50

0.6 (1.1)

  • Pt100

-200 … +850
(-328 … +1562)

100

0.3 (0.5)

  • Pt200

-200 … +850
(-328 … +1562)

100

0.6 (1.1)

  • Pt500

-200 … +850
(-328 … +1562)

100

1.0 (1.8)

  • Pt1000

-200 … +850
(-328 … +1562)

100

1.0 (1.8)

JIS C 1604-81

  • Pt10

-200 … +649
(-328 … +1200)

20

3.0 (5.4)

  • Pt50

-200 … +649
(-328 … +1200)

50

0.6 (1.1)

  • Pt100

-200 … +649
(-328 … +1200)

100

0.3 (0.5)

DIN 43760

  • Ni50

-60 … +250
(-76 … +482)

50

0.3 (0.5)

  • Ni100

-60 … +250
(-76 … +482)

100

0.3 (0.5)

  • Ni120

-60 … +250
(-76 … +482)

100

0.3 (0.5)

  • Ni1000

-60 … +250
(-76 … +482)

100

0.3 (0.5)

Resistance-based sensor

Input

Measuring range

Max. permissible line resistance

Digital error

Ω

Ω

Ω

Resistance (linear)

0 … 24

5

0.08

0 … 47

15

0.06

0 … 94

30

0.06

0 … 188

50

0.08

0 … 375

100

0.1

0 … 750

100

0.2

0 … 1500

75

1.0

0 … 3000

100

1.0

0 … 6000

100

2.0

Thermocouples

Input

Measuring range

Digital error 1)

°C / (°F)

°C (°F)

Type B

100 … +1820
(+212 … +3308)

3 (5.4)

Type C

0 … +2300
(+32 … +4172)

2 (3.6)

Type D

0 … +2300
(+32 … +4172)

1 (1.8)

Type E

-200 … +1000
(-328 … +1832)

1 (1.8)

Type J

-210 … +1200
(-346 … +2192)

1 (1.8)

Type K

-200 … +1372
(-328 … +2501)

1 (1.8)

Type L

-200 … +900
(-328 … +1652)

2 (3.6)

Type N

-200 … +1300
(-328 … +2372)

1 (1.8)

Type R

-50 … +1760
(-58 … +3200)

2 (3.6)

Type S

-50 … +1760
(-58 … +3200)

2 (3.6)

Type T

-200 … +400
(-328 … +752)

1 (1.8)

Type U

-200 … +600
(-328 … +1112)

2 (3.6)

1) Accuracy data refer to the largest error in the complete measuring range

Voltage/current sources

Input

Measuring range

Digital error

mV sources (linear)

mV

μV

-1  … +16

35

-3 … +32

20

-7 … +65

20

-15 … +131

50

-31 … +262

100

-63 … +525

200

-120 … +1000

300

V sources (linear)

V

mV

-1.2 … +10

3

-12 … +100

30

-120 … +140

300

μA/mA sources (linear)

μA/mA

μA

-12 … +100 μA

0.05

-120 … +1000 μA

0.5

-1.2 … +10 mA

5

-12 … + 100 mA

50

-120 … +1000 mA

500