Technical Specifications
| Parameter | Value |
|---|---|
| Product Model | 6ES5252-3AA13 |
| Manufacturer | Siemens AG |
| Product Type | SIMATIC S5 IP 252 Closed-Loop Control Module |
| Product Family | SIMATIC S5 (Technology Module) |
| Compatible Hosts | S5-135U / S5-155U (central rack or EU expansion); S5-115U per configuration |
| Control Loops | 1 × independent closed-loop algorithm kernel |
| Control Algorithms | PID / PD / P (parametrizable) |
| Sampling Time | 1 ms – 250 ms (parametrized) |
| Setpoint Resolution | 12-bit + sign |
| Actual-Value Resolution | 12-bit + sign |
| Analog Input (X6) | Differential ±10 V, ±20 mA, 0–20 mA (config via submodule) |
| Analog Output (X6) | ±10 V, 0–20 mA, 4–20 mA |
| Encoder Interface (X4) | Incremental encoder link to IP240 counter module (3AA13 A04+ required for IP240 coupling) |
| Memory Submodule (X3) | 48-pin DIN 41612; 32 K EPROM (controller structure) + 8 K EEPROM (parameters) |
| Backplane Supply | 5 V DC from S5 rack |
| Auxiliary Supply | 24 V DC (M24V) |
| Programming/Configuration | STEP 5 + COM REG IP 252 or COM REG GRAPHIC IP 252 |
| Mounting Method | Single S5 rack slot |
| Operating Temperature | 0 °C to +60 °C |
| Weight | 1.01 kg |
| Customs Code | 85371091 |
| Lifecycle Status | Obsolete since 01-Apr-2012 (Siemens official) |
| RoHS Compliance | Not RoHS-compliant (legacy class) |
| Country of Origin | Germany |
Main Features and Advantages
Hardware-level PID offloads the CPU: The defining advantage of the 6ES5252-3AA13 is its dedicated closed-loop algorithm kernel that executes PID, PD, or P control in hardware—completely independent of the S5-135U/155U CPU scan cycle. This architectural separation means the 6ES5252-3AA13 can run a deterministic 1 ms loop even while the CPU is busy handling sequencing, communication, and I/O updates. For applications where control latency directly impacts product quality—web tension on a rolling mill, velocity control on a servo axis, pressure regulation in a hydraulic system—the 6ES5252-3AA13 delivers microsecond-class correction that pure software PID simply cannot achieve. This hardware-level approach transforms a legacy S5-135U/155U into a precision motion and process controller without any CPU upgrade.
Flexible sampling and high-resolution signal handling: With a sampling time adjustable from 1 ms to 250 ms and 12-bit + sign resolution on both setpoint and actual-value paths, the 6ES5252-3AA13 adapts to processes spanning the full speed spectrum—from fast servo loops requiring 1 ms response to slow thermal processes comfortable at 250 ms. The differential analog inputs (±10 V, ±20 mA, 0–20 mA) reject common-mode noise in electrically hostile industrial environments, while the configurable analog outputs (±10 V, 0–20 mA, 4–20 mA) drive a wide range of actuators, valves, and drives. This signal flexibility means the 6ES5252-3AA13 interfaces directly with virtually any industrial sensor or final control element without signal conditioning add-ons.
Encoder-coupled feed-forward capability: The X4 interface of the 6ES5252-3AA13 (on 3AA13 A04+ firmware) links to an IP240 counter module, allowing the closed-loop kernel to consume a speed or position word as feed-forward input. This architecture splits “counting” from “controlling” across two submodules on the same backplane—the IP240 captures encoder pulses while the 6ES5252-3AA13 consumes the speed word to anticipate load changes before they manifest as error. The result is dramatically improved dynamic response in tension control, unwinding/rewinding stations, and synchronized drive systems, all without migrating to a modern motion controller.
DRS controller structure in EPROM: The 6ES5252-3AA13 stores its controller structure (DRS—the firmware-level definition of how the PID, feed-forward, and limiters are interconnected) in a 32 K EPROM submodule on the X3 port, while an 8 K EEPROM holds the actual tuning parameters. This separation means the control architecture is portable, version-controlled, and swappable—a maintenance technician can replace a failed 6ES5252-3AA13 by simply transferring the memory submodule, instantly restoring the exact control behavior without re-commissioning. This design philosophy reflects Siemens’ deep understanding of industrial reality, where reproducibility and minimal downtime trump convenience.
Seamless S5-135U/155U integration: The 6ES5252-3AA13 draws 5 V DC from the rack backplane and 24 V DC (M24V) for field-side circuitry, requiring no external power supply module of its own. It occupies a single S5 rack slot and communicates with the CPU through the native S5 system bus, making it visible to STEP 5 as a standard technology module. Configuration is performed through the COM REG IP 252 or COM REG GRAPHIC IP 252 software packages, which provide graphical tuning, trending, and controller structure design—a level of engineering tooling that belies the module’s 1980s origins.
Availability as a professionally refurbished MRO spare: Although Siemens has declared the 6ES5252-3AA13 obsolete since April 2012, specialized automation suppliers now offer fully overhauled, bench-tested units with 12- to 24-month warranties. Every refurbished 6ES5252-3AA13 undergoes component-level inspection, EPROM/EEPROM verification, X6 analog loop-back testing, X4 encoder link validation, and full PID execution verification before shipment. This ensures the module performs identically to the original Siemens factory build, preserving the integrity of legacy closed-loop systems that cannot be easily migrated.
