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Availability: Obsolete
OBSOLETE SNAP 2-Ch Isolated -20 to +20 mA Analog Current Input Module with Loop Sourcing

Production Specification

*** NOTE: This part is obsolete and no longer available. ***
Please consider SNAP-AIMA-iSRC or contact Opto 22 Pre-Sales engineers for more information.

The SNAP-AIMA-iSRC-FM provides two isolated channels of -20 mA to +20 mA analog current and also includes built-in loop sourcing capability. With the connection of a single 24 V power supply, the module sources 24 V for two 4–20 mA loops. The loops are internally connected to the individual inputs. The two channels and their loop sources are isolated from each other.

Part of the SNAP PAC System, the module mounts on a SNAP PAC rack with a SNAP PAC brain or rack-mounted controller. Analog, digital, and serial I/O modules can all be on the same rack. Such an I/O unit is also well suited for PC-based control or for use as intelligent remote I/O for an Allen-Bradley Logix PLC system, such as ControlLogix, MicroLogix, or CompactLogix.

Other options:
  • If you do not need loop sourcing, see SNAP-AIMA-i.
  • ‚ÄčIf you do not need channel-to-channel isolation, see SNAP-AIMA.
Build your system in the SNAP I/O Configurator.
*** This part is OBSOLETE and no longer available. ***

Input Range

0 to +20 mA with loop sourcing
-20 mA to +20 mA

Maximum Over Range

± 10%
(= ± 27500 counts)


0.8 µA

Input Response Time
(% of span/delta I/delta time)

99.9 %/19.9 mA/10 ms

Data Freshness

11 ms

DC Common Mode Rejec­tion

>-120 dB

AC Common Mode Rejec­tion

>-120 dB @ 60 Hz

Maximum Survivable Input

36 mA or 9 VDC

Maximum Operating
Common Mode Voltage

250 V


0.05% (10 µA)

DRIFT: Gain Temperature

30 PPM/ °C

DRIFT: Offset Temperature

15 PPM/ °C

Isolation: Optical

4000 V

Isolation: Transformer

1500 V

Isolation: Channel to Chan­nel

250 V continuous
(1500 V transient)

Power Requirements

5 VDC (±0.15) @ 200 mA

Power Requirements -
Loop Power (Input)

From separate field connector:
24 VDC nominal (70 mA max @ 24 V input, both loops @ 20 mA),
30 VDC maximum

Loop Power (Output)

24 VDC (± 1.5 V) @ 20 mA
Open loop: 30 V maximum
Shorted loop: 24 mA nominal

LED on top of module

Indicates that there is power to the 24v source supply 2-pin connector

Input Resistance

200 ohms (each channel)

Ambient Temperature:


-20 °C to 70 °C
-40 °C to 85 °C


5-95%, non-condensing

Torque, hold-down screws

Not to exceed 1 in-lb (0.11 N-m)

Torque, connector screws

5.22 in-lb (0.59 N-m)

Wire size range

22 to 14 AWG

Agency Approvals




Obsolete SNAP Analog I/O Modules Technical Note

This technical note contains information you may need about OBSOLETE SNAP analog I/O modules you’re still
using. Included are part numbers, descriptions, specifications, wiring diagrams, and dimensional drawings.
These parts have been removed from data sheets because we no longer sell them.

This document includes information on the following obsolete SNAP analog I/O modules:

Opto 22 RoHS 3 Statement of Compliance - Restriction of Hazardous Substances

This document is a statement of compliance with the EU Directive 2015/863/EU, Restriction of Hazardous Substances (RoHS 3). This document lists Opto 22 products that comply with the substance restrictions of the RoHS 3 directive.

CE Declaration: Low Voltage

This document is the Manufacturer's Declaration for the listed products as mentioned in the attachment - to which this confirmation refers - that they are in accordance with the mentioned European, international and/or national standards and regulations.

No downloads are available for this product.

Video: SNAP PAC System Overview

This overview describes the four integrated components of the SNAP PAC system: software, controllers, brains and I/O. This hardware and software system is designed for industrial control, remote monitoring and data acquisition.

Video: Securing SNAP Module

A quick overview on securing a SNAP Module to a SNAP rack.

Video: Removing a SNAP Module

A quick overview on removing a SNAP module.

Accuracy vs Resolution

What's the difference between accuracy and resolution in analog I/O specifications? Try your own specs in the calculator.