Impulse SCM7B39 User Manual

Isolated Process Control Signal Conditioning Products

SCM7B39

Isolated Process Current Output Modules

Description

SCM7B39 process current modules accept high level signals from the process

control system and provide either 0 to 20mA or 4 to 20mA current to the field

(Figure 1).

These modules incorporate a five-pole filtering approach to maximize both time

and frequency response by taking advantage of both Thomson (Bessel) and

Butterworth characteristics. One pole of the filter is on the process control system

side of the isolation barrier, and the other four poles are on the field side.

After the initial process control system side filtering, the signal is chopped by a

proprietary chopper circuit and transferred across the transformer isolation

barrier, suppressing transmission of common mode spikes and surges. The

signal is then reconstructed, filtered, and converted to a process current for

output to the field.

Modules accept a wide 18 - 35VDC power supply range (+24VDC nominal).

Their compact packages (2.13"x1.705"x0.605" max) save space and are ideal

for high channel density applications. They are designed for easy DIN rail

mounting using any of the -DIN backpanels.

SCM7B

▲

Features

 Accepts High Level Voltage Input

 Provides 4-20mA or 0-20mA Current Output

 1500Vrms Transformer Isolation

 Accuracy, ±0.03% of Span Typical, ±0.1%

Max

 ANSI/IEEE C37.90.1 Transient Protection

 Output Protected to 120Vrms Continuous

 Noise, 46µA Peak (5MHz), 4µA RMS

(100kHz)

 CMRR, 110dB

 80dB Per Decade of Attenuation Above 100Hz

 Easy DIN Rail Mounting

 CSA Certified, FM Approved

 CE and ATEX Compliant

Figure 1: SCM7B39 Block Diagram

For information call 800-444-7644

Isolated Process Control Signal Conditioning Products

SCM7B

Specifications

Typical at 25°C and +24VDC

Module SCM7B39-01,-02,-03 SCM7B39-04

Output

Signal Range

Effective Available Power

Protection

Continuous 120Vrms max *

Transient ANSI/IEEE C37.90.1 *

Current Limit 32mA *

Input

Signal Range 1 to +5V, 0 to +10V 4-20mA

Bias Current ±1nA N/A

Resistance

Protection ±35Vpeak (no damage) ±7.5Vpeak

Compliance N/A 35VDC max

CMV (Input-to-Output)

Continuous 1500Vrms *

Transient ANSI/IEEE C37.90.1 *

CMRR (50 or 60Hz) 110dB *

Accuracy

Nonlinearity

Stability (-40°C to +85°C)

Gain ±25ppm/°C ±50ppm/°C

Output Offset ±0.0035% Span/°C ±0.0045% Span/°C

Noise

Peak at 5MHz B/W 46µA *

RMS at 10Hz to 100kHz B/W 4µA *

Peak at 0.1Hz to 10Hz B/W 42nA *

Open Output Loop Detection

Response N/A Input Resistance

Detection Time N/ A 5ms

Frequency and Time Response

Bandwidth, -3dB 100Hz *

NMR (-3dB at 100Hz) 80dB per decade above 100Hz *

Step Response, 90% Span 5m s *

Supply Voltage 18 to 35VDC *

Current

Sensitivity ±0.0003%/%V

Mechanical Dimensions 2.13" x 1.705" x 0.605" max *

(h)(w)(d) 54.1mm x 43.3mm x 15.4mm max *

Environmental

Operating Temperature Range -40°C to +85°C *

ATEX Group II, Category 3 -20°C to +40°C *

Storage Temperature Range -40°C to +85°C *

Relative Humidity 0 to 95% noncondensing *

Emissions EN61000-6-4 ISM, Group 1 *

Radiated, Conducted Class A *

Immunity EN61000-6-2 ISM, Group 1 *

R F Performance A ±0.5% Span Error *

ESD, EFT, Surge, Voltage Dips Performance B *

NOTES:

* Same specification as SCM7B39-01, -02, -03

(1) Output Range and Supply Current specifications are based on maximum output load resistance. Maximum output

load resistance is calculated by P

accuracy, and linearity specifications. Output effective available power is independent of supply voltage.

(2) Accuracy includes the effects of repeatability, hysteresis, and linearity.

Nonlinearity is calculated using the best-fit straight line method.

(3)

(1)

4-20mA, 0-20mA 4-20mA

320mW *

Normal 10MΩ 270Ω Power Off 30kΩ min >20kΩ Overload 30kΩ min N/ A

(2)

(3)

±0.03% Span typical, *

±0.1% Span max

±0.01% Span typical, *

±0.02% Span max

> 20kΩ

(1)

where PE is the Output Effective Available Power that guarantees output range,

E/IOUT

56mA *

Ordering Information

Model Input Range Output Range

SCM7B39-01 +1 to +5V 4 to 20mA

SCM7B39-02 0 to +10V 0 to 20mA

SCM7B39-03 0 to +10V 4 to 20mA

SCM7B39-04 4 to 20mA 4 to 20mA

SCM7B

Visit our website www.dataforth.com