Siemens ed1055-1mb00-0ba2

By Abdullah Zahid
12 min read
Siemens 6ED1055-1MB00-0BA2 LOGO! DM8 12/24R digital expansion module mounted on DIN rail in industrial control panel

Siemens 6ED1055-1MB00-0BA2 LOGO! DM8 12/24R Expansion Module: Specs, Wiring Overview, and Selection Guide

Controls engineers expanding a LOGO! 8 installation hit a familiar decision point: add a larger base controller, or extend the existing one with a dedicated I/O module. The Siemens 6ED1055-1MB00-0BA2 — officially the LOGO! DM8 12/24R Expansion Module — answers that question directly with 4 digital inputs and 4 floating relay outputs, powered from a 12-24V DC supply, in a DIN-rail-mounted package that connects directly to the LOGO! 8 expansion port. If you are validating this SKU against your project requirements, this guide covers specs, application fit, wiring considerations, and honest variant comparisons so you can commit to the right part the first time.

If you have already confirmed this is the right part, check current pricing and availability at LeadTime.ca — ships worldwide.

Who Should Buy the 6ED1055-1MB00-0BA2 — and Who Shouldn't

The 6ED1055-1MB00-0BA2 is the right choice when you need a compact, cost-effective way to add exactly 4 digital inputs and 4 relay outputs to a LOGO! 8 system. It fits well when all of the following are true:

  • Your base controller is a LOGO! 8 unit — this module does not connect to LOGO! 7 or any earlier generation
  • You require exactly 4 digital inputs at 12-24V DC and 4 floating relay output contacts
  • A 12-24V DC power supply is available or planned at the mounting location
  • Your relay loads draw no more than 5A per contact under steady-state conditions
  • DIN rail space is available in the control enclosure for an adjacent module mount

If you need analog inputs or outputs, the LOGO! AM2 is the correct module. If your relay loads exceed 5A per contact, or if you require AC-rated digital inputs, a different module family is required. For I/O counts beyond what 4 DI and 4 DO can provide, evaluate other LOGO! DM8 variants before ordering.

On this page:

What the LOGO! DM8 12/24R Actually Does in a Control System

The 6ED1055-1MB00-0BA2 is a plug-in digital I/O expansion module for the LOGO! 8 programmable controller family. It adds 4 digital inputs rated at 12-24V DC and 4 floating relay output contacts rated at 5A per contact — without requiring any additional programming hardware or software beyond the existing LOGO! 8 environment. The module connects directly to the expansion connector on the right side of the LOGO! 8 base unit and draws power from a 12-24V DC supply, which can be positioned remotely from the main controller.

Its core value is straightforward: system integrators and controls engineers using LOGO! 8 as a standard platform report 20-40% cost savings by expanding with DM8 modules compared to replacing the base controller with a larger multi-slot PLC chassis. Rather than upsizing the entire control platform to accommodate a handful of additional I/O points, the 6ED1055-1MB00-0BA2 lets you extend capacity at a fraction of the cost while keeping the programming environment identical. The module carries active product status, and Siemens maintains availability for field systems over a 5-10+ year horizon — a meaningful factor for plant maintenance managers ordering spares today.

The 2 MW of onboard memory and floating relay contact design support standard LOGO! 8 ladder logic without any special configuration. The floating contacts allow connection to both AC and DC loads within the rated current, giving the module flexibility across solenoid valve control, motor starter energization, and indicator lamp circuits in the same installation.

Typical System Architecture for LOGO! 8 with DM8 Expansion

The 6ED1055-1MB00-0BA2 sits as a satellite I/O node directly adjacent to or downstream of the LOGO! 8 base unit, extending the controller's reach to sensors and actuators that would otherwise require long cable runs back to the main enclosure.

  • 12-24V DC power supply feeds both the LOGO! 8 base unit and the 6ED1055-1MB00-0BA2 module at the panel or field enclosure
  • LOGO! 8 base unit connects to the 6ED1055-1MB00-0BA2 via the dedicated expansion connector port on the base unit's right side
  • Digital sensors (limit switches, proximity sensors, pushbuttons) wire into the 4 digital input terminals on the module
  • Relay output contacts connect to downstream loads — solenoid valves, motor starters, indicator lamps, or contactors — within the 5A per contact rating
  • Additional LOGO! DM8 or AM2 modules can be stacked further right to build out total system I/O as the application demands

Where This Module Gets Deployed: Industries and Use Cases

Packaging machinery integrators frequently deploy the 6ED1055-1MB00-0BA2 to control solenoid valves at remote stations on a line and aggregate limit switch inputs from satellite conveyor sections — eliminating the cost of running individual signal cables back to a central panel across a long machine frame.

In building automation and HVAC control, the module handles pump or fan motor starter energization and accepts flow or temperature switch inputs for monitoring. The floating relay contacts support both AC and DC load circuits, which matters in mixed-voltage HVAC panels where 24V DC control logic coexists with 120V AC motor circuits.

Water and waste treatment facilities use the 6ED1055-1MB00-0BA2 for multi-point pump and valve control from a single LOGO! 8 controller, consolidating alarm and fault inputs from distributed sensors without investing in a full distributed I/O network. The relay contact life expectancy of 100,000-500,000 operations under normal switching loads makes it practical for pumping duty cycles in these environments.

OEM equipment builders standardizing on LOGO! 8 as a base platform add multiple DM8 modules to customize the final I/O count per customer order, reducing design cycle time by keeping the core controller identical across machine variants.

Application Typical Deployment
Packaging Machinery Remote solenoid valve control and limit switch input aggregation at satellite conveyor sections
HVAC and Building Automation Motor starter energization for pumps and fans, flow/temperature switch monitoring
Water and Waste Treatment Multi-point pump and valve control, alarm input consolidation from distributed sensors
Discrete Manufacturing Cost-effective retrofit to add monitoring and control of additional equipment without replacing main controller
OEM Equipment Integration Stacked DM8 modules on LOGO! 8 base platform to customize I/O count per customer machine specification

Purchase-Decision Specs and LOGO! Expansion Module Comparison

Parameter Value
Power Supply 12-24V DC
Digital Inputs 4 (12-24V DC)
Relay Output Contacts 4 floating contacts
Relay Contact Rating 5A per contact
Memory 2 MW
Compatible Base Unit LOGO! 8 only
Mounting DIN Rail (standard)
Product Release Date 08/31/2014
Life Cycle Status Active Product
LOGO! 7 / Earlier Generation Compatible No — incompatible connector and drivers

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

LOGO! 8 Expansion Module Variant Comparison

Module Model I/O Type Digital Inputs Outputs Relay Rating Compatible Base Best Use Case
6ED1055-1MB00-0BA2 Digital 4 DI 4 DO Relay 5A LOGO! 8 General small systems, standard relay loads
6ED1055-1MM00-0BA2 Digital (Variant) 4 DI 4 DO Relay 5A LOGO! 8 Regional alternative with equivalent I/O count
LOGO! AM2 Analog 2 AI 1 AO Variable LOGO! 8 Temperature, pressure, and process control inputs
LOGO! DM8 variants Digital 2-8 2-8 Relay 5A-10A LOGO! 8 Custom I/O expansion for higher point counts or higher relay ratings

If your architecture requires analog process inputs or outputs, the LOGO! AM2 is the correct choice — check current availability of the 6ED1055-1MB00-0BA2 at LeadTime.ca while confirming your module mix.

Expert Verdict: When This Module Earns Its Place and When It Doesn't

The 6ED1055-1MB00-0BA2 does exactly what it promises: it extends a LOGO! 8 system with 4 digital inputs and 4 floating relay outputs at minimal cost and with zero learning curve for any engineer already working in the LOGO! 8 environment. For OEM builders, packaging integrators, and plant engineers retrofitting small control panels, this is a well-supported, actively stocked part that avoids the cost and complexity of upsizing to a larger PLC platform. The relay contact life expectancy of 100,000-500,000 operations and the active product status backed by Siemens' extended availability commitment make it a credible long-term choice for systems that will need spare parts in the field for years.

Where this module has genuine limits: the 5A per contact rating is not suitable for direct connection of large motor loads or solenoid banks that draw higher current — an external contactor becomes mandatory in those scenarios. The 4 DI and 4 DO count is fixed; if your design evolves to require 6 or 8 points per module, you will need a different DM8 variant or a second module, which affects enclosure space planning. And critically, this part is LOGO! 8 exclusive — if there is any uncertainty about whether the installed base unit is LOGO! 7 or LOGO! 8, that must be resolved before ordering because the expansion connector is physically incompatible across generations.

On the procurement side, the 6ED1055-1MB00-0BA2 is generally available through authorized distributors with standard lead times in the 2-4 week range, with expedited options at premium cost. Volume pricing discounts are common for system integrators building multiple machines on the same platform. If this matches your system requirements, view current stock and pricing at LeadTime.ca — we ship to customers worldwide.

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

The following points cover the key requirements and configurations to verify before and during installation. For full wiring diagrams and step-by-step procedures, refer to the Siemens LOGO! 8 system manual and the module's official documentation.

  • The module mounts on DIN rail directly adjacent to the LOGO! 8 base unit and connects via the expansion connector port on the base unit's right side — power must be removed from the base unit before seating the module
  • Digital inputs accept 2-wire and 3-wire sensor connections at 12-24V DC; shielded twisted pair cable is recommended for signal runs longer than 5 meters to minimize digital noise
  • Relay output terminals are floating contacts — confirm whether your load circuit requires normally open, normally closed, or changeover contact configuration before wiring, and verify the load current does not exceed 5A per contact
  • A dedicated 12-24V DC regulated power supply for the module should be protected with a fuse or industrial circuit breaker; do not share the LOGO! 8 base unit supply without isolation
  • After physical installation, verify module recognition in the LOGO! 8 programming environment and confirm input and output address mapping before energizing connected loads

Compatible Modules and LOGO! 8 System Expansion

The 6ED1055-1MB00-0BA2 is one of several expansion modules that plug into the LOGO! 8 expansion connector chain. The following modules are part of the same LOGO! 8 ecosystem and can be combined with this unit to build a complete I/O mix:

  • 6ED1055-1MM00-0BA2 — Digital expansion module variant with 4 DI and 4 DO relay at 5A, serving as a regional or availability alternative with equivalent I/O specification
  • LOGO! AM2 — Analog expansion module providing 2 analog inputs and 1 analog output for temperature, pressure, or process signal monitoring within the same LOGO! 8 program environment
  • LOGO! DM8 variants (2-8 DI, 2-8 relay DO, 5A-10A contact ratings) — Higher I/O count or higher relay rating options when 4 DI and 4 DO at 5A is insufficient for the application

All compatible expansion modules connect to the LOGO! 8 base unit through the same right-side expansion connector and are addressed automatically within the LOGO! 8 programming software. No module is compatible with LOGO! 7 or earlier generation base units.

Wrong-Part Prevention Checklist Before You Order

Before placing an order for the 6ED1055-1MB00-0BA2, work through each item on this checklist. These are the most common points where ordering errors occur with LOGO! expansion modules:

  1. Verify the base controller is LOGO! 8, not LOGO! 7, LOGO! 5, or other generation.
  2. Confirm that 4 digital inputs and 4 relay outputs match the automation requirement (not fewer, not more, not analog).
  3. Check that the 12-24V DC power supply is available on site or will be installed.
  4. Verify the relay contact 5A rating is sufficient for downstream devices (motors, solenoids, lights).
  5. Confirm that floating relay contacts are appropriate for the application (not normally-open-only or normally-closed-only fixed types).
  6. Check that the module is ordered for LOGO! 8 and not as a spare part for a LOGO! 7 system already in the field.
  7. Verify regional availability through authorized distributors to avoid ordering obsolete or non-stocked variants.
  8. Confirm installation clearance and DIN rail space in the control enclosure.

If any item on this checklist raises a question before ordering, contact the LeadTime.ca team to confirm the correct part for your application — or view the product page for current specification documentation and availability.

Frequently Asked Questions

Will the 6ED1055-1MB00-0BA2 work with my existing LOGO! 7 installation?

No. The 6ED1055-1MB00-0BA2 is compatible with LOGO! 8 base units only. The expansion connector is physically different from LOGO! 7 and earlier generations, and the software drivers are not interchangeable. If your installed controller is LOGO! 7, you need an expansion module specifically rated for that generation — or a LOGO! 8 migration plan.

Can I connect a motor directly to the relay output contacts on this module?

Only if the motor's steady-state current draw does not exceed 5A per relay contact. For larger motors or solenoid banks that draw higher current, the correct approach is to wire the LOGO! relay output to control an external contactor or motor starter rated for the actual load current. Using an undersized relay contact on an overloaded circuit causes contact welding and loss of control.

How many 6ED1055-1MB00-0BA2 modules can I stack on one LOGO! 8 base unit?

The brief does not specify a maximum module count per base unit — refer to the Siemens LOGO! 8 system manual for the official expansion capacity limit for your specific base unit model. What is confirmed is that multiple DM8 and AM2 modules can be stacked via the expansion connector chain to build out total system I/O.

What is the typical lead time for the 6ED1055-1MB00-0BA2 through an authorized distributor?

Standard order lead time is typically 2-4 weeks from authorized distributor stock. Expedited options are available at premium cost, potentially reducing lead time to 1-2 weeks. Major distributors including LeadTime.ca maintain stock of this module given its active product status. For a confirmed lead time on your specific order quantity, contact LeadTime.ca directly.

Does the 6ED1055-1MB00-0BA2 require any additional software or licensing to use?

No additional software licensing is required beyond the existing LOGO! 8 programming environment. The module is recognized automatically by the LOGO! 8 base unit upon connection and its I/O addresses are mapped within the standard LOGO! 8 software. No separate configuration tool or driver installation is documented in the brief.

What is the difference between the 6ED1055-1MB00-0BA2 and the 6ED1055-1MM00-0BA2?

Both modules provide 4 digital inputs and 4 relay output contacts at 5A, and both are compatible with LOGO! 8 base units. The 6ED1055-1MM00-0BA2 is identified in the brief as a regional alternative variant with equivalent I/O specification. If your distributor has availability constraints on one variant, the other may be a practical substitute — confirm with your supplier that the specific application requirements are met before substituting.

Why Order the 6ED1055-1MB00-0BA2 From LeadTime.ca

  • LeadTime.ca ships the 6ED1055-1MB00-0BA2 and compatible LOGO! 8 expansion modules worldwide — no geographic restrictions on sourcing
  • Volume pricing is available for system integrators ordering multiple modules for multi-machine builds on a LOGO! 8 standard platform
  • The team can confirm stock status and committed lead times before you finalize a build schedule — reducing the risk of procurement delays on active projects
  • Hard-to-find or short-lead-time variants in the LOGO! expansion module family can be sourced through LeadTime.ca's distributor network

At-a-Glance Summary

  • Official product name: LOGO! DM8 12/24R Expansion Module, catalog number 6ED1055-1MB00-0BA2
  • 4 digital inputs at 12-24V DC and 4 floating relay output contacts at 5A per contact
  • Power supply requirement: 12-24V DC
  • 2 MW onboard memory; DIN rail mounting; active product status since 08/31/2014
  • Compatible with LOGO! 8 base units only — not compatible with LOGO! 7, LOGO! 5, or any earlier generation
  • System integrators report 20-40% cost savings using DM8 expansion versus replacing the LOGO! 8 base controller with a larger chassis
  • Relay contact life expectancy: 100,000-500,000 operations depending on load — supports standard maintenance intervals in HVAC, pump control, and solenoid applications
  • Typical distributor lead time: 2-4 weeks standard; 1-2 weeks expedited at premium cost
  • Siemens maintains active availability for field spares over a 5-10+ year horizon for this part number
  • Wrong-part risk: always confirm LOGO! 8 generation and verify relay load current against the 5A per contact rating before ordering