SCM5B35-02D

Isolated Analog Signal Conditioning Products S C M 5 B SCM5B35 Linearized 4-Wire RTD Input Modules Description In RTD temperature measurement applications requiring a very high level of accuracy, the SCM5B35 4-Wire RTD input module offers a significant advantage over wire measurement techni ues Figure 1). The SCM5B35 measures only the voltage dropped across the RTD and almost completely ignores the resistance or length of the RTD lead wires. The SCM5B34 3-Wire RTD module provides lead resistance compensation, but re uires e ual lead resistances, while the S B does not require matched lead resistances. Each SCM5B35 RTD input module provides a single channel of RTD input which is filtered, isolated, amplified, lineari ed, and converted to a high-level analog voltage output. This voltage output is logic switch controlled, which allows these modules to share a common analog bus without the requirement of external multiplexers. The SCM5B modules are designed with a completely isolated computer side circuit which can be oated to from Power ommon, pin . This complete isolation means that no connection is re uired between I O Common and Power Common for proper operation of the output switch. If desired, the output switch can be turned on continuously by simply connecting pin , the Read nable pin, to I O ommon, pin . Features Interfaces to Platinum, or Nic el RTDs opper, • True 4-Wire Input • Linearizes RTD Signal • High-Level Voltage Output • 1500Vrms Transformer Isolation • ANSI/IEEE C37.90.1 Transient Protection • Input Protected to 240VAC Continuous • 160dB CMR • 95dB NMR at 60Hz, 90dB at 50Hz SA S ertified • CE and ATEX Compliant • Mix and Match SCM5B Types on Backpanel RTD excitation is provided from the module by a precision current source. The excitation current is available on two leads which are separate from the two input signal measuring leads. The excitation current does not ow in the input signal leads, which allows RTD measurement to be totally independent of lead resistance. The excitation current is very small . mA for Pt and Ni and . mA for u which minimizes self-heating of the RTD. of this filter are on the field side of the isolation barrier, and the other four are on the computer side. After the initial field side filtering, the input signal is chopped by a proprietary chopper circuit. Isolation is provided by transformer coupling, again using a proprietary technique to suppress transmission of common mode spikes or surges. The module is powered from +5VDC, ± 5%. Signal filtering is accomplished with a six pole filter which provides 95dB of normal-mode rejection at 60Hz and 90dB at 50Hz. Two poles A special input circuit on the SCM5B35 modules provides protection against accidental connection of power-line voltages up to 240VAC. F i g u r e 1 : S C M 5 B 3 5 B l o ck D ia g r a m 1 4 ©1995-2017 Dataforth Corporation, All Rights Reserved For information call 800-444-7644 ISO9001:2008-Registered QMS Specifications Typical❇ at TA Module Input Range Limits Input Resistance Normal Power Off Overload Input Protection Continuous Transient Sensor Excitation Current Pt, Ni u Lead Resistance Effect Pt, Ni u CMV, Input to Output Continuous Transient CMR (50Hz or 60Hz) NMR and Ordering Information D power SCM5B35 to to to Pt Ni u 240Vrms max ANSI/IEEE C37.90.1 0.25mA 1.0mA . . (1) 1500Vrms max ANSI/IEEE C37.90.1 160dB 95dB at 60Hz, 90dB at 50Hz See Ordering Information ± 0.025% Span Output Range Output Resistance Output Protection Output Selection Time (to ± 1mV of VOUT) Output Current Limit See Ordering Information Continuous Short to Ground s at load = 0 to 2000pF Output nable ontrol Max Logic “0” Min Logic “1” Max Logic “1” Input Current “0,1” +0.8V +2.4V +36V . A Power Supply Voltage Power Supply Current Power Supply Sensitivity Pt, Ni u Mechanical Dimensions (h)(w)(d) Environmental Operating Temperature Range Storage Temperature Range Relative Humidity Emissions EN61000-6-4 Radiated, Conducted Immunity EN61000-6-2 RF ESD, EFT Pt SCM5B35-01 to F to F SCM5B35-02 to F to F SCM5B35-03 to F to F SCM5B35-04 to F to F SCM5B35-05 to F to F to at F to F to at F to F to at F to F to F to F Cu SCM5B35C-01 SCM5B35C-02 . ppm of Reading . rms rms 4Hz 0.2s +8mA Downscale Non-deterministic 3s +5VDC ± 5% 30mA . . 2.28” x 2.26” x 0.60” (58mm x 57mm x 15mm) to to 0 to 95% Noncondensing ISM, Group 1 Class A ISM, Group 1 Performance A ± 0.5% Span Error Performance B Output Range† Input Range (1) Accuracy Conformity Error(3) Stability Input Offset Output Offset Gain Noise Input, 0.1 to 10Hz Output, 100kHz Bandwidth, – 3dB Response Time, 90% Span Open Input Response Lead 1,4 Lead 2,3 Open Input Detection Time Model SCM5B35C-03 i SCM5B35N-01 ** Accuracy(2) 3, 4 . 3, 4 . 3, 4 . 3, 4 . 3, 4 . 3, 4 . 3, 4 . 3, 4 . 3, 4 . RTD Standards Alpha Coe ficient Type Pt Ni u 0.00385 0.00672 0.004274 DIN JIS IEC DIN 43760 JIS C 1604-1989 IEC 751 Output Ranges Available † Output Range Part o u fi 3. 0V to +5V 4. 0V to +10V NONE D am e SCM5B35-01 SCM5B35-01D NOTES : ❇ ontact factory or your local Dataforth sales office for maximum values. refers to the resistance in one lead. Includes conformity, hysteresis and repeatability. (3) Conformity error is ± 0.05% Span for SCM5B35N-01. Visit our website www.dataforth.com ©1995-2017 Dataforth Corporation, All Rights Reserved 1 5 ISO9001:2008-Registered QMS S C M 5 B S C M 5 B Isolated Analog Signal Conditioning Products