Siemens 6ED1052-1MD08-0BA1 LOGO! 12/24RCE — Specs & Buying Guide

By Abdullah Zahid
13 min read
Siemens 6ED1052-1MD08-0BA1 LOGO! 12/24RCE logic module with display mounted on 35mm DIN rail for industrial automation

Siemens 6ED1052-1MD08-0BA1 LOGO! 12/24RCE Logic Module with Display — Specs, Selection, and Setup Guide

If you are a controls engineer or procurement specialist evaluating compact logic modules for a small-to-medium automation task, the Siemens 6ED1052-1MD08-0BA1 LOGO! 12/24RCE Logic Module with Display is likely already on your shortlist. This base unit of the SIEMENS LOGO! 8 Automation Platform delivers 8 digital inputs (4 of which convert to 0–10 V analog), 4 dry-contact relay outputs, integrated Ethernet with a built-in web server, and a 24-hour real-time clock with 480-hour battery backup — all in a 71.5 mm wide DIN rail footprint. The decision comes down to whether 4 relay outputs and 400 function blocks cover your application, and whether your cabinet has 12 or 24 V DC supply available.

If you have already confirmed this is the right part, check current pricing and availability for the 6ED1052-1MD08-0BA1 at LeadTime.ca — ships worldwide.

Does the Siemens 6ED1052-1MD08-0BA1 Fit Your Project Requirements?

This module is the right choice when your application matches all of the following criteria:

  • Your cabinet supplies 12 V DC or 24 V DC — the permissible operating range is 10.8–28.8 V DC; no AC input variant exists for this model
  • Your DIN rail has at least 4 spacing units (approximately 72 mm) free on a standard 35 mm profile
  • Your application requires no more than 8 digital inputs and 4 relay outputs at the base unit level
  • Your relay loads are resistive at or below 10 A per output, or inductive at or below 3 A per output — and you can accommodate external fusing, which the datasheet explicitly mandates
  • Your logic program fits within 400 function blocks
  • Ethernet connectivity and an integrated web server are either needed or acceptable as a convenience feature

If you need analog outputs rather than additional relay outputs, the 6ED1052-1MD08-0BA2 variant is the correct alternative. If your program will exceed 400 function blocks or your application requires certified safety functions such as SIL-rated emergency stop interlocks, a SIMATIC S7-1200 series module is the more appropriate platform.

On this page:

What the Siemens 6ED1052-1MD08-0BA1 Actually Does in a Control System

The 6ED1052-1MD08-0BA1 is the primary logic processing and I/O control module in a LOGO! 8 automation system. It reads field signals through 8 digital inputs, executes a user-defined program using up to 400 function blocks — including timers, counters, analog comparators, and waveform generators — and switches field devices through 4 dry-contact relay outputs rated at 10 A resistive or 3 A inductive per output. All of this logic runs locally, without dependency on an external controller or network.

Two features of the 6ED1052-1MD08-0BA1 stand out at the purchase decision stage. First, the integrated 24-hour real-time clock with 480-hour battery backup means time-based automation schedules persist through power interruptions of up to 20 days without any external timekeeping device. Second, the front-mounted display and membrane keyboard allow local parameter viewing, clock setting, forced I/O testing, and fault diagnosis without a connected PC — a practical advantage for sites where laptop access is inconvenient or where maintenance technicians are not running LOGO! Soft Comfort. These two capabilities together make this model specifically well suited for building HVAC control, sequential pump scheduling, and small batch applications where site access and standalone operation are priorities.

The Ethernet port at 10/100 Mbps includes an integrated web server that supports user-definable HTML pages, real-time variable display, and CSV data logging for up to 10 variables at configurable sample rates. A MicroSD card slot supports project backup and field updates using Soft Comfort V8.3 or later, reducing the need for a direct PC connection during commissioning or program updates.

Typical System Architecture for the LOGO! 12/24RCE

The 6ED1052-1MD08-0BA1 sits at the center of a LOGO! 8 automation node — downstream of the power supply, upstream of field devices, and optionally connected to a local network or SCADA system via Ethernet.

  • 24 V DC power supply feeds L+ and 0 V terminals on the base unit; external fusing on the supply branch is recommended
  • Field sensors (switches, proximity sensors, 0–10 V transmitters) wire directly to the 8 digital input terminals — 4 of which can be configured as 0–10 V analog inputs in the Soft Comfort project
  • The 6ED1052-1MD08-0BA1 executes the stored program and switches its 4 relay outputs to control contactors, solenoid valves, motor starters, or indicator loads — each output requiring an external fuse upstream
  • LOGO! 8 expansion modules (digital I/O, analog I/O, or communication cards) mount adjacent on the same 35 mm DIN rail and connect via the integrated expansion interface on the right side of the base unit
  • The Ethernet port connects to a local network switch, HMI, or remote monitoring system; the integrated web server provides browser-based access without additional software on the viewing device

Where Engineers Deploy This Logic Module

Sequential pump control with time-based scheduling is one of the most common deployments for the 6ED1052-1MD08-0BA1. A two- or three-pump system with pressure or temperature feedback on 0–10 V analog inputs, alternating pump duty cycles controlled by the real-time clock, and relay outputs switching motor starters fits precisely within the 8 DI / 4 DO / 400-block architecture of this module.

In food and beverage or packaging environments, the module handles batch recipe execution using stored function blocks, with setpoint alarms on analog inputs triggering relay-switched warning devices or conveyors. The MicroSD slot allows recipe parameters to be updated in the field without a PC present.

Building HVAC automation — occupancy-based thermostat control, damper scheduling, and manual override logic — suits this module well because the real-time clock with 480-hour backup maintains scheduling through weekend or holiday shutdowns. The web server provides remote monitoring for facilities managers who need visibility without a full SCADA deployment.

OEM machine builders use the 6ED1052-1MD08-0BA1 as a compact base unit for limited-function machine controllers: dryers, ovens, small press controls, and conveyor starters where the total I/O count fits within the base unit or with one expansion module, and where a local display simplifies operator interaction at the machine.

Application Typical Deployment
Sequential pump control 2–3 pumps, relay outputs to motor starters, 0–10 V pressure/temperature input, RTC-based alternation
Multi-stage dryer or oven Relay-triggered heater stages, analog setpoint comparators, alarm relay output, local display for operator setpoints
Building HVAC automation Occupancy-based scheduling via 480-hour RTC, relay-switched dampers, web server for remote monitoring
Conveyor starter logic Digital inputs from load sensors and safety guards, relay outputs to contactors, local keyboard for manual override
Batch recipe execution Stored function blocks for sequence steps, MicroSD for recipe upload, CSV data logging via Ethernet
Facility pump and motor starter Compact DIN rail installation, relay outputs to motor starters, Ethernet to building management network

Purchase-Critical Specifications at a Glance

Parameter Specification
Rated Supply Voltage 12 V DC or 24 V DC (auto-detect)
Permissible Voltage Range 10.8–28.8 V DC
Digital Inputs 8 inputs, 0–24 V DC; 4 of 8 convertible to 0–10 V analog
Digital Outputs 4 dry-contact relay outputs (NO/NC); 10 A resistive / 3 A inductive per output
Relay Contact Voltage Range 0–300 V AC / 0–48 V DC
Function Blocks (max) 400
Real-Time Clock Battery Backup 480 hours (20 days)
Ethernet 10/100 Mbps, RJ45; integrated web server
Operating Temperature -20°C to +55°C (no condensation)
Dimensions (W × H × D) 71.5 mm × 90 mm × 60 mm; 4 DIN rail spacing units on 35 mm profile

Full technical specifications are available on the product page at LeadTime.ca.

6ED1052-1MD08-0BA1 vs. -0BA2 vs. S7-1200: Which One Do You Actually Need?

Model Outputs Analog Outputs Function Blocks Best For
6ED1052-1MD08-0BA1 (this model) 4 relay DO None (4 AI inputs only) 400 Standard automation with balanced digital I/O, relay-switched loads
6ED1052-1MD08-0BA2 2 relay DO + 2 analog outputs 2 analog outputs 400 Multi-loop PID control (heating/cooling) requiring analog signal output
SIMATIC S7-1200 base unit Higher I/O density Available Exceeds 400 Programs exceeding 400 blocks, structured text programming, multi-protocol SCADA

If your application is standard relay-output switching with up to 4 analog input channels and 400 logic blocks, the 6ED1052-1MD08-0BA1 is the correct choice — check current availability and pricing at LeadTime.ca.

Expert Verdict: Honest Assessment for Engineers at the Decision Stage

The 6ED1052-1MD08-0BA1 delivers a well-balanced combination of features for its footprint. The 71.5 mm width consuming only 4 DIN spacing units is compact enough for tight panels. The front display and keyboard are genuinely useful — not just a marketing point — because maintenance technicians can check live values, set clock parameters, and force-test outputs without a laptop or network access. The 480-hour battery backup on the real-time clock means time-based schedules survive extended shutdowns without needing external battery-backed RTCs. The 400-function-block limit is sufficient for the vast majority of small machine and building control applications that this module targets. These three characteristics — display, clock backup, and 400 blocks in a 72 mm footprint — are the reasons buyers choose this model specifically over alternatives.

The honest limitations are equally clear. The 4 relay output count is a hard ceiling at the base unit level; if your application grows beyond that, expansion modules are needed, adding cost and DIN rail space. More critically, the datasheet explicitly states that external fusing is mandatory for every relay output — this is not optional. Engineers who overlook this during panel design have experienced relay contact damage from inductive load transients, particularly with solenoid valves and motor brakes. Plan your external fuse strategy before you finalize the panel layout. The module also carries no SIL or PLd safety certification, meaning it cannot be the controlling element for safety-rated emergency stop circuits or interlocked guards — a hardwired safety relay or certified F-CPU is required for those functions. If your specification sheet calls for certified safety functions, this model is not the correct choice regardless of its other merits.

From a procurement standpoint, the 6ED1052-1MD08-0BA1 is a well-stocked, high-volume part. Typical lead times from major distributors are 1–2 weeks when in stock, with factory-order lead times of 4–8 weeks in tight supply periods. If you are ordering multiple units for an OEM build or a phased facility rollout, volume pricing is available — contact LeadTime.ca directly to discuss. If this module matches your system requirements, view current stock and pricing at LeadTime.ca.

For volume pricing or to confirm lead time before committing to a build, contact the LeadTime.ca team directly — we ship worldwide.

Wiring and Installation Overview

  • Mount on a standard 35 mm DIN rail with at least 4 spacing units (approximately 72 mm) available; horizontal mounting is standard, vertical is permitted if noted in the Soft Comfort project configuration
  • Supply 12 V DC or 24 V DC to the L+ and 0 V terminals; the module auto-detects voltage within the 10.8–28.8 V DC permissible range — install a supply branch fuse before the module
  • Wire digital inputs to the DI terminals using switch contacts (no external pull-up needed) or sourced 24 V DC signals; for analog use, configure pins 5–8 as analog inputs in the Soft Comfort project before wiring 0–10 V signals — failure to set this in software is the most common cause of erratic analog readings
  • Each relay output provides a dry contact (NO/NC selectable in software) — wire the load circuit through the relay contact and install an external fuse in series with the load supply upstream of each contact; for inductive loads (solenoids, motor coils), fit a freewheeling diode or varistor suppressor across the coil
  • Use shielded twisted-pair cabling for any analog input runs longer than 5 m, and route analog signal cables away from high-current power conductors to prevent ADC interference; connect Ethernet to the RJ45 port for Soft Comfort program download and web server access

Compatible Expansion Modules for the LOGO! 8 Platform

The 6ED1052-1MD08-0BA1 connects to LOGO! 8 expansion modules via the integrated connector interface on the right side of the base unit. Expansion modules mount adjacent on the same 35 mm DIN rail. If your application requires additional I/O beyond the 8 DI / 4 DO base configuration, the following expansion paths are available based on brief data:

  • Additional relay or digital outputs via LOGO! digital output expansion modules — for applications where 4 relay outputs are insufficient and the 400-block program limit is not yet reached
  • Analog input expansion for 4–20 mA or 0–20 mA signals, where the base unit's 0–10 V analog inputs are not compatible with the sensor signal type
  • Modbus RTU communication via an optional external gateway when serial fieldbus integration is required — Ethernet is built into the base unit but Modbus RTU requires an additional interface
  • When 3 or fewer additional I/O points are needed and program memory remains under 400 blocks, expansion modules are the cost-effective path; if more than 5 expansion modules would be required or the program exceeds 400 blocks, evaluate the SIMATIC S7-1200 platform instead

What Engineers Get Wrong When Ordering This Part

Before submitting a purchase order for the 6ED1052-1MD08-0BA1, verify all six of the following points — these are the failure modes that generate returns, field rework, and project delays:

  1. Verify supply voltage is 12 or 24 V DC available in your cabinet; 10.8–28.8 V DC is permissible but not wider
  2. Confirm DIN rail has at least 4 spacing units (approx 72 mm) available and rated for 35 mm profile
  3. Check relay output load requirements (max 10 A per output at 0–55°C; max 3 A per relay if inductive load); if higher, size external contactor
  4. Ensure external fusing is specified (datasheet explicitly states "external fusing necessary"; short-circuit protection is not integrated)
  5. Verify Ethernet infrastructure exists if cloud/web server functions are essential; can operate without but core display/local logic function does not depend on it
  6. Confirm 4 analog inputs (0–10 V) are sufficient; if more analog channels needed, select -0BA2 variant or add expansion module

If any item on this checklist flags a mismatch, contact the LeadTime.ca team to confirm the correct variant before ordering — we ship worldwide and can advise on alternative configurations.

Frequently Asked Questions

Does the 6ED1052-1MD08-0BA1 require an external fuse on every relay output?

Yes — the Siemens datasheet explicitly states that external fusing is necessary for each relay output. There is no integrated short-circuit protection or circuit breaker inside the module. Each output should have an appropriately rated fuse upstream of the relay contact, sized to the load: typically up to 10 A for resistive loads and 3 A for inductive loads. For inductive loads, add a freewheeling diode or varistor across the coil to suppress transient voltage spikes that can damage relay contacts over time.

How many analog inputs does the 6ED1052-1MD08-0BA1 actually have?

The base unit has 8 digital inputs, of which 4 can be configured as 0–10 V analog inputs — this configuration must be set in the Soft Comfort software project before the inputs will accept analog signals. The analog resolution is 8-bit. If you need more than 4 analog input channels, or if your sensors output 4–20 mA rather than 0–10 V, you will need to add an analog expansion module or select the -0BA2 variant which adds analog output capability.

What happens to the real-time clock if power is lost for more than 20 days?

The integrated battery backup on the 6ED1052-1MD08-0BA1 retains the real-time clock for 480 hours, which is approximately 20 days. If power is interrupted for longer than that — or if the internal battery has depleted — the clock resets to 00:00 and time-based function blocks will not execute correctly until the clock is manually reset via the front keyboard or remotely via Ethernet. Battery replacement typically becomes necessary every 5–10 years depending on usage.

Can this module be used for safety-rated emergency stop functions?

No. The 6ED1052-1MD08-0BA1 and the LOGO! 8 platform are not certified for SIL or PLd safety-critical functions. Emergency stop circuits, interlocked guards, and other safety-rated functions must be implemented with hardwired safety relays or a certified F-CPU from the SIMATIC S7 series. Your operator documentation must explicitly state that E-stop and guarding are separate from this module's control logic.

How do I download a program to the 6ED1052-1MD08-0BA1 without a USB port on the module?

Program transfer is performed via the Ethernet port using LOGO! Soft Comfort V8.3 or later. The default IP address of the module is 192.168.1.1. Alternatively, programs can be transferred and backed up using the MicroSD card slot, which is the preferred method for field updates when a direct PC connection is not practical. An optional USB communications module is available if USB transfer is specifically required.

What is the difference between the 6ED1052-1MD08-0BA1 and the 6ED1052-1MD08-0BA2?

Both variants share the same 400-function-block memory, Ethernet port, display, and 480-hour clock backup. The -0BA1 (this model) provides 4 dry-contact relay digital outputs and no analog outputs — suited for standard relay-switched automation. The -0BA2 reduces relay outputs to 2 and adds 2 analog outputs, making it the correct choice for multi-loop PID applications such as heating and cooling control where an analog signal must be sent to a proportional valve or variable speed drive.

Why Order the 6ED1052-1MD08-0BA1 from LeadTime.ca

  • LeadTime.ca ships the Siemens 6ED1052-1MD08-0BA1 worldwide — no regional restrictions on quoting or fulfillment
  • Current stock levels and real pricing are visible on the product page without requiring an account or quote request for standard quantities
  • Volume pricing is available for OEM builders and multi-unit procurement — contact the team directly to discuss order quantities and lead time commitments
  • Hard-to-source or long-lead variants can be expedited or sourced through LeadTime.ca's distributor network
  • The team can confirm compatibility with expansion modules and advise on variant selection before an order is placed

At-a-Glance Summary

  • Model: Siemens 6ED1052-1MD08-0BA1 — LOGO! 12/24RCE Logic Module with Display, part of the SIEMENS LOGO! 8 Automation Platform
  • Supply voltage: 12 V DC or 24 V DC rated; 10.8–28.8 V DC permissible operating range
  • I/O: 8 digital inputs (4 convertible to 0–10 V analog) and 4 dry-contact relay outputs at 10 A resistive / 3 A inductive
  • Relay contact voltage range: 0–300 V AC / 0–48 V DC — external fusing is mandatory per output
  • Logic capacity: 400 function blocks maximum
  • Real-time clock with 480-hour (20-day) battery backup for time-based scheduling
  • Connectivity: 10/100 Mbps Ethernet with integrated web server, MicroSD slot for Soft Comfort V8.3+ project backup
  • Footprint: 71.5 mm × 90 mm × 60 mm; 4 spacing units on 35 mm DIN rail
  • Operating temperature: -20°C to +55°C; storage: -40°C to +70°C
  • Certifications: CE, UL, CSA, FM, Marine (NK), IEC 61131, VDE 0631
  • Not SIL/PLd certified — safety-critical functions require a separate certified safety module
  • Choose -0BA2 variant if analog outputs are needed; choose SIMATIC S7-1200 if program exceeds 400 blocks or safety functions are mandatory