Siemens S7-200 SMART Modules – 6ES7288-3AR02-0AA0

Technical Dossier

Product Details And Specifications

Siemens S7-200 SMART Series Technical Notes

The Siemens S7-200 SMART series is a compact programmable logic controller (PLC) platform engineered for small-to-medium automation applications. Deployed extensively across chemical processing plants, water treatment facilities, textile manufacturing lines, packaging systems, and light industrial infrastructure across Asia, Europe, and the Middle East, the S7-200 SMART represents Siemens' successor architecture to the legacy S7-200 (6ES7 2xx) platform. Its modular expansion bus, Ethernet-native CPU variants, and compatibility with STEP 7-Micro/WIN SMART programming software have made it a standard reference design in OEM machine building and process skid automation. The 6ES7288-3AR02-0AA0 is a 2-channel RTD analog input expansion module within this series, designed for precision temperature measurement via resistance thermometers (Pt100, Pt1000, Cu50, Ni100).

The Evolution of S7-200 SMART Architecture

The S7-200 SMART platform was introduced by Siemens circa 2012 as a cost-optimized successor to the S7-200 (Classic) series, which reached end-of-sale status in 2017. The Classic S7-200 used the 6ES7 2xx-0xx00-0XB0 naming convention and relied on the PPI/MPI serial bus for inter-device communication. The SMART generation introduced a standardized Ethernet port on all CPU variants, replaced the proprietary expansion bus connector with a higher-density interface, and added motion control and PID loop capabilities natively in firmware.

Key architectural transitions: the original SMART V1.0 CPUs (circa 2012–2014) lacked onboard analog I/O; V2.0 (2015–2018) introduced integrated analog inputs on select CPU models; V2.3 and V2.4 (2019–present) added enhanced motion axis support and expanded signal board options. Expansion modules (EM series, prefix 6ES7288-3xx) have remained backward-compatible across all CPU generations, making the 6ES7288-3AR02-0AA0 and its siblings interchangeable across the full SMART CPU lineup. As of 2024, the S7-200 SMART remains in active production, though Siemens positions the S7-1200 (6ES7 214-xxx) as the strategic migration path for new designs requiring TIA Portal integration.

S7-200 SMART Full Catalog & Functionalities (SKU List)

CPU Modules

6ES7288-1SR20-0AA0: CPU SR20, 12DI/8DO relay, 12KB prog memory, Ethernet.
6ES7288-1SR30-0AA0: CPU SR30, 18DI/12DO relay, 18KB prog memory, Ethernet.
6ES7288-1SR40-0AA0: CPU SR40, 24DI/16DO relay, 24KB prog memory, Ethernet.
6ES7288-1SR60-0AA0: CPU SR60, 36DI/24DO relay, 30KB prog memory, Ethernet.
6ES7288-1ST20-0AA0: CPU ST20, 12DI/8DO transistor (sourcing), 12KB prog memory.
6ES7288-1ST30-0AA0: CPU ST30, 18DI/12DO transistor, 18KB prog memory, Ethernet.
6ES7288-1ST40-0AA0: CPU ST40, 24DI/16DO transistor, 24KB prog memory, Ethernet.
6ES7288-1ST60-0AA0: CPU ST60, 36DI/24DO transistor, 30KB prog memory, Ethernet.

Digital Input (DI) Expansion Modules

6ES7288-2DE08-0AA0: EM DE08, 8-channel 24VDC digital input expansion module.
6ES7288-2DE16-0AA0: EM DE16, 16-channel 24VDC digital input expansion module.

Digital Output (DO) Expansion Modules

6ES7288-2DR08-0AA0: EM DR08, 8-channel relay digital output, 2A per channel.
6ES7288-2DR16-0AA0: EM DR16, 16-channel relay digital output expansion module.
6ES7288-2DT08-0AA0: EM DT08, 8-channel transistor (sourcing) digital output module.
6ES7288-2DT16-0AA0: EM DT16, 16-channel transistor digital output expansion module.

Analog Input (AI) Expansion Modules

6ES7288-3AE04-0AA0: EM AE04, 4-channel analog input, 0–10V / 0–20mA / 4–20mA.
6ES7288-3AE08-0AA0: EM AE08, 8-channel analog input, voltage/current configurable per channel.
6ES7288-3AR02-0AA0: EM AR02, 2-channel RTD analog input; supports Pt100, Pt1000, Cu50, Ni100 resistance thermometers. Resolution: 0.1°C. Range: –200°C to +850°C (Pt100).

Analog Output (AO) Expansion Modules

6ES7288-3AQ02-0AA0: EM AQ02, 2-channel analog output, 0–10V / 0–20mA selectable.
6ES7288-3AQ04-0AA0: EM AQ04, 4-channel analog output, voltage/current configurable.

Thermocouple (TC) Input Modules

6ES7288-3AT04-0AA0: EM AT04, 4-channel thermocouple input; supports J, K, T, E, R, S, B, N type TC.

Signal Boards (SB – CPU-mounted)

6ES7288-5BA01-0AA0: SB BA01, 1DI/1DO signal board, mounts directly on CPU face.
6ES7288-5AE01-0AA0: SB AE01, 1-channel analog input signal board, 12-bit resolution.
6ES7288-5AQ01-0AA0: SB AQ01, 1-channel analog output signal board, 0–10V / 0–20mA.

Sourcing Hard-to-Find & Obsolete S7-200 SMART Parts

Although the S7-200 SMART series remains in active Siemens production as of 2026, specific module variants — particularly early V1.x CPU units, discontinued signal board revisions, and regional-market SKUs — are no longer available through standard distribution channels. DriveKNMS maintains a dedicated inventory of both current-production and end-of-life S7-200 SMART modules sourced through authorized secondary-market channels, factory-surplus liquidations, and direct OEM partnerships.

Quality Control for the S7-200 SMART Range

S7-200 SMART modules present specific verification challenges due to their high-density expansion bus connector, firmware version dependencies, and analog signal chain calibration requirements. DriveKNMS applies a structured test protocol to all S7-200 SMART units prior to dispatch:

CPU Modules: Power-on self-test (POST) verification, Ethernet port link/activity confirmation, program memory read/write cycle test using STEP 7-Micro/WIN SMART V2.4+, RUN/STOP mode transition validation, and onboard I/O point-by-point functional check.

Analog Input Modules (including 6ES7288-3AR02-0AA0): RTD channel calibration verification using decade resistance box at 0Ω, 100Ω (0°C Pt100), and 138.5Ω (100°C Pt100) reference points. Differential linearity and offset error measured against Siemens published accuracy specification (±0.3% full scale). Channel isolation integrity test.

Digital I/O Modules: All input channels tested with 24VDC stimulus; all output channels loaded at rated current (relay: 2A resistive; transistor: 0.75A). Relay contact resistance measured (<100mΩ acceptance threshold).

Expansion Bus Interface: Bus connector pin continuity and impedance verified. Module recognized and enumerated correctly when connected to reference CPU in test rig.