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

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.

Product No. / Product Description Listprice / Your price

7NG3242-…..

SITRANS TW universal transmitter for rail mounting in four-wire system

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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 (R_RTD ≤ 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 U_rmsbetween 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 I_AN or U_AN	≤ 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 I_AN or U_AN	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