Siemens 6ES7136-6BA00-0CA0 — ET 200SP Safety Input Buying Guide

By Abdullah Zahid
14 min read
Siemens 6ES7136-6BA00-0CA0 F-DI 8x 24V DC HF failsafe digital input module for ET 200SP distributed safety I/O

Siemens 6ES7136-6BA00-0CA0 — SIMATIC DP, Electronic Module for ET 200SP, F-DI 8x 24 V DC HF, 15 mm Width: Specs, Features, and Selection Guide for ET 200SP Safety Input Modules

Controls engineers specifying safety-rated distributed I/O for emergency stop circuits, machine guarding, or conveyor interlock systems typically arrive at this page with one question already answered: they need a failsafe digital input module on the ET 200SP platform. The remaining question is whether the Siemens 6ES7136-6BA00-0CA0 — an F-DI 8x 24 V DC HF module rated to PL E (ISO 13849-1) and SIL 3 (IEC 61508) in a 15 mm wide housing — is the exact right variant for their build. This guide gives you the specification detail, variant comparison, and wrong-part checklist to confirm that answer before you commit to a purchase order.

If you have already validated this is the correct part, check current pricing and availability for the 6ES7136-6BA00-0CA0 at LeadTime.ca — ships worldwide.

Who Should Buy the 6ES7136-6BA00-0CA0 — and Who Shouldn't

This module is the right choice for engineers who need a certified failsafe input interface within an existing or planned ET 200SP distributed I/O architecture. Specifically, it fits your project if all of the following are true:

  • Your application demands safety certification at PL E (ISO 13849-1) or SIL 3 (IEC 61508) — such as emergency stop circuits, safety-interlocked gates, or conveyor shutdown systems.
  • You require exactly 8 digital input channels at 24 V DC, with encoder supply outputs rated to 800 mA total across all eight outputs.
  • Your enclosure or DIN rail layout requires the compact 15 mm ET 200SP form factor.
  • Your system runs PROFIBUS DP or PROFINET via an ET 200SP backplane configured with BU type A0 base units.
  • Your engineering environment is STEP 7 TIA Portal v12 or later, or STEP 7 v5.5 SP3 or later.

If your application does not require a safety certification, a standard (non-failsafe) DI module will cost less and is the more appropriate choice. If you need more than 8 inputs per module, 16-input and 32-input variants are available in the ET 200SP family. If any of your input signals are 110 V or 230 V AC, this module cannot be used directly — a different module family is required.

On this page:

What the 6ES7136-6BA00-0CA0 Actually Does in a Safety System

The Siemens 6ES7136-6BA00-0CA0 is a safety-rated digital input module — part designation F-DI 8x 24 V DC HF — designed for the SIMATIC ET 200SP distributed I/O platform. It reads eight 24 V DC signals from field devices such as safety switches, emergency stop push-buttons, and position sensors, applies failsafe input logic rated to PL E and SIL 3, and transmits the evaluated signal states to the central PLC via the ET 200SP backplane. Alongside its eight input channels, the module also provides eight 24 V DC encoder supply outputs, delivering up to 800 mA total to power connected sensors and encoders directly from the module — eliminating the need for a separate sensor power rail in many installations.

The module weighs 49 g, draws only 70 mW from the backplane, and occupies a 15 mm wide slot in the ET 200SP rack. Its design life is specified at 20 years. The probability of dangerous failure on demand over that 20-year service life is less than 2.00E-05, and the probability of dangerous failure per hour in high-demand mode is less than 1.00E-09 — figures that support compliance documentation under both ISO 13849-1 and IEC 61508 without requiring external safety relay modules in many configurations.

Two characteristics make this module particularly attractive in decentralized safety architectures: first, its 15 mm width allows multiple modules to be mounted close together in compact control panels or junction boxes near the machine; second, the integrated encoder supply outputs mean a single module handles both signal reading and sensor power, which reduces terminal count, wiring labor, and panel space simultaneously.

Typical System Architecture for ET 200SP Failsafe I/O

The 6ES7136-6BA00-0CA0 sits at the field edge of a distributed safety I/O network, sitting between the central safety PLC and the physical sensors or safety switches on the machine. Its role is to translate hardwired 24 V DC field signals into failsafe digital data that the controller can act on.

  • Central safety PLC (SIMATIC S7-300, S7-400, or S7-1500 with F-CPU) connects via PROFIBUS DP or PROFINET to one or more ET 200SP stations distributed across the machine or production line.
  • Each ET 200SP station consists of a PROFIBUS DP or PROFINET interface module mounted on an ET 200SP backplane rail with BU type A0 base units.
  • The 6ES7136-6BA00-0CA0 plugs into a BU type A0 slot and appears as an F-DI 8x 24 V DC HF module in the STEP 7 TIA Portal hardware configuration.
  • Field devices — emergency stop buttons, safety gate switches, light curtain outputs, encoder feedback signals — connect to the module's 24 V DC input terminals; the module's encoder supply outputs power the sensor electronics directly.
  • Diagnostic LED indicators (RUN, ERROR, PWR, DIAG) provide local fault visibility at the module, while channel-level diagnostics are reported back to the PLC program for alarm handling and safe-state management.

Where This Module Gets Deployed: Industries and Machine Types

Automotive assembly lines are one of the most common deployment environments for the 6ES7136-6BA00-0CA0. Welding cells, transfer lines, and robotic work cells use multiple instances of this module — one per work station — to monitor emergency stop buttons, safety gate closures, and light curtain status signals. The decentralized architecture means a fault at one station does not cascade to adjacent zones.

Food and beverage processing facilities use this module to interlock access doors on mixers, fillers, and conveyors. Because the module carries PL E / SIL 3 certification with an EU Declaration of Conformity and UL approval, it supports CE marking under the Machinery Directive (2006/42/EC) without requiring a separate safety relay for the input circuit.

Machine tool manufacturers specify the 6ES7136-6BA00-0CA0 to monitor spindle guard closures and axis travel limits. The module's 0.4 ms parameterizable input delay and cable length support up to 1000 m (shielded) make it viable even in large-format CNC machines with long cable runs from the control cabinet to the machine bed.

Conveyor system integrators use the module's eight inputs to read belt misalignment sensors, pull-cord switches, and zero-speed detectors, while the encoder supply outputs power the sensors directly. The 800 mA total encoder supply budget comfortably covers a full complement of inductive proximity sensors or photoelectric safety sensors at this channel count.

Pharmaceutical and packaging lines with ISO-compliant safety architectures benefit from the module's SIL 3 rating, which satisfies the most demanding process safety requirements encountered in those sectors. The module also carries DNV, ABS, and Lloyd's Register maritime certifications, making it suitable for offshore and marine automation installations.

Application Typical Deployment
Emergency stop circuits Eight failsafe inputs monitor E-stop push-buttons and safety relays across a production cell
Machine guarding and interlocked gates Inputs verify gate/enclosure closure status before permitting high-speed machine operation
Conveyor belt safety monitoring Inputs read belt motion, misalignment, and pull-cord switches; encoder outputs power proximity sensors
Encoder feedback in motion control Module supplies 24 V DC to position/speed encoders and reads failsafe status signals
Modular machine safety (one module per work station) Decentralized safety logic reduces central PLC load and isolates zone faults
Offshore and marine automation DNV, ABS, and Lloyd's Register certifications support safety I/O in marine environments

Purchase-Decision Specs: What You Need to Know Before You Order

Specification Value
Number of Digital Inputs 8
Input Voltage (Rated) 24 V DC
Signal "1" Voltage Range +15 to +30 V
Total Encoder Supply Current (max) 800 mA
Safety Rating PL E (ISO 13849-1) / SIL 3 (IEC 61508)
Module Width 15 mm
Power Consumption from Backplane 70 mW
Operating Temperature (horizontal) 0 to 60°C
Cable Length — Shielded / Unshielded 1000 m / 500 m
Required Base Unit Type BU type A0 only

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

6ES7136-6BA00-0CA0 vs. 6ES7136-6BA01-0CA0 and Other Alternatives

Feature 6ES7136-6BA00-0CA0 (This Model) 6ES7136-6BA01-0CA0
Product Type F-DI 8x 24 V DC HF (Failsafe) F-DI 8x 24 V DC HF (Failsafe)
Safety Rating PL E / SIL 3 PL E / SIL 3
Number of Inputs 8 8
Input Voltage 24 V DC 24 V DC
Module Weight 49 g 29 g
Max Current (backplane) 21 mA 40 mA
Encoder Supply Yes Yes
Suitable for Safety Functions Yes Yes
Primary Difference Standard failsafe configuration Reduced weight; verify compatibility before substituting

Both variants carry the same PL E / SIL 3 safety rating and support identical input channel counts — the 6ES7136-6BA01-0CA0 differs primarily in weight (29 g vs. 49 g) and backplane current draw (40 mA vs. 21 mA). If your backplane power budget is tight and you are evaluating the -0CA0 variant, confirm that the higher backplane current of the -01 alternative does not cause a budget overrun before considering a substitution. For the vast majority of standard safety applications, the 6ES7136-6BA00-0CA0 is the catalog-recommended choice — check current availability at LeadTime.ca.

For non-safety applications, the 6ES7136-6AE00-0CA0 is a standard (non-failsafe) DI 8x 24 V DC variant that costs less but carries no PL E or SIL 3 certification. Specifying it in a safety-critical circuit will cause a project to fail regulatory inspection — a costly and time-consuming error. If you need more than 8 inputs per module, 16-input and 32-input ET 200SP variants exist; use those where channel density matters more than distributed zone isolation.

Expert Verdict: Is This Module Worth Specifying?

The 6ES7136-6BA00-0CA0 earns its place on the BOM for any ET 200SP safety architecture that requires PL E / SIL 3 rated digital inputs in a compact enclosure. The combination of eight failsafe inputs, eight encoder supply outputs at 800 mA total, a 15 mm housing, and a 70 mW backplane power draw is genuinely hard to match without stepping up to a larger module or adding external components. The design life of 20 years and a high-demand failure probability of less than 1.00E-09 per hour provide the hard numbers that safety documentation reviews typically demand — you are not relying on a third-party safety relay to achieve SIL 3; the module itself carries the certification. UL, CCC, KC, EAC, DNV, ABS, and Lloyd's Register approvals mean it qualifies for deployment in markets worldwide without additional compliance work.

The honest limitations are narrow but worth stating. This module only accepts 24 V DC inputs — if any signal in the circuit is 110 V or 230 V AC, a different module is required and there is no workaround. It is also restricted to BU type A0 base units; if your ET 200SP station was built with a different base unit type, you cannot simply drop this module in. And if your project has no safety certification requirement, the standard DI variant will deliver the same signal-reading functionality at lower cost. None of these are design flaws — they are scope boundaries that the brief lays out clearly — but they catch engineers who do not cross-check part numbers before purchasing. If this matches your system requirements, view current stock and pricing at LeadTime.ca.

On the procurement side, the 6ES7136-6BA00-0CA0 is classified as a spare part in the Siemens catalog — not obsolete — and is generally available through major automation distributors with typical lead times of 5 to 15 business days. Firmware version V2.0 is current; confirm your supplier stocks the latest firmware revision. For safety-critical installations, carrying a spare module in inventory is worth considering — the downtime cost of an unplanned failure on a safety-interlocked line typically dwarfs the cost of stocking one additional unit.

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 module requires a BU type A0 ET 200SP base unit — automatic encoding electronics handle module recognition on insertion; no manual jumper or DIP switch setting is required. Verify the backplane power supply can deliver 70 mW to the module before seating.
  • Input signals are 24 V DC only. Signal "0" is recognized in the -30 to +5 V range; signal "1" requires +15 to +30 V. Use shielded twisted-pair cable for runs up to 1000 m; unshielded cable is acceptable up to 500 m. Label both ends of each signal pair at installation.
  • The module's eight encoder supply outputs provide 24 V DC at a minimum of L+ -1.5 V. Each individual output is rated for 0.3 A at up to 60°C ambient; total current across all eight outputs must not exceed 800 mA. Calculate the combined load of all connected sensors and encoders before installation.
  • Electronic short-circuit protection on encoder supply outputs activates at 0.7 to 1.8 A. If a short circuit is detected, the affected output is deactivated automatically; resolve the fault condition and cycle module power to restore normal operation.
  • After installation, confirm module status using the onboard LED indicators: RUN (green) indicates normal operation, PWR (green) confirms backplane supply is stable, ERROR (red) signals a fault condition, and DIAG (green/red) reflects channel-level diagnostic status. Verify input state changes in STEP 7 TIA Portal by manually toggling sensors during commissioning.

Compatible Modules and System Expansion

The 6ES7136-6BA00-0CA0 operates within the SIMATIC ET 200SP distributed I/O ecosystem. The following module types and system components are relevant to a complete ET 200SP safety I/O station:

  • ET 200SP BU type A0 base units — the only compatible base unit type for this module; available in multiple terminal configurations for different field wiring requirements.
  • ET 200SP PROFIBUS DP or PROFINET interface modules — gateway modules that connect the ET 200SP backplane rail to the main communication network; required for every ET 200SP station.
  • ET 200SP F-DO (failsafe digital output) modules — complement the F-DI 8x 24 V DC HF in safety architectures where failsafe actuator control is also required at the same station.
  • ET 200SP power modules — provide segmented load power for groups of I/O modules on the same backplane, supporting isolation between safety and standard I/O zones.
  • STEP 7 TIA Portal (v12 or later) with SIMATIC STEP 7 Safety Advanced — required for configuring failsafe modules; standard TIA Portal without the Safety Advanced option cannot configure F-DI modules.

Wrong-Part Prevention Checklist — Read Before You Order

Ordering errors on safety I/O modules cause project delays that are disproportionately expensive — a non-failsafe module in a safety circuit means a full rework cycle, not just a parts swap. Verify every item below before submitting a purchase order for the 6ES7136-6BA00-0CA0:

  1. Confirm you require failsafe (F-DI) digital inputs, not standard (DI) inputs. Non-failsafe variants have part numbers ending in -6AE00 or -6BA01.
  2. Verify your ET 200SP base unit is BU type A0 compatible. Other base unit types require different module versions.
  3. Check that your central PLC supports STEP 7 TIA Portal v12 or later; earlier versions cannot configure this module.
  4. Confirm all eight input signals are 24 V DC. If any signal is 110 V or 230 V, this module cannot be used directly.
  5. Verify total encoder supply current requirement does not exceed 800 mA across all eight outputs.
  6. Check that your backplane power supply can deliver 70 mW to the module's power consumption requirement.

If any item on this checklist raises a flag, contact LeadTime.ca before ordering — the team can help confirm the correct variant for your application and check current stock worldwide.

Frequently Asked Questions

Can the 6ES7136-6BA00-0CA0 replace the 6ES7136-6BA01-0CA0 directly?

Both modules share the same PL E / SIL 3 safety rating, 8-channel input count, and 24 V DC input voltage. The key difference is that the -0CA0 draws 21 mA from the backplane while the -6BA01-0CA0 draws 40 mA, and the two modules differ in weight (49 g vs. 29 g). Before substituting, verify your backplane power budget, confirm BU type A0 compatibility, and check that your STEP 7 project hardware configuration accepts the replacement module revision without requiring a full project update.

What happens if the total encoder supply current exceeds 800 mA?

The module's electronic short-circuit protection activates between 0.7 A and 1.8 A per output channel. If the total load across all eight encoder supply outputs exceeds 800 mA, individual output channels may trip the protection threshold. The affected output deactivates automatically; the fault is reported via the DIAG LED and to the PLC program. To avoid this in service, calculate the sum of all connected sensor and encoder currents before installation and use an external 24 V contactor or separate power supply if the load exceeds the module's rated budget.

Is STEP 7 TIA Portal Safety Advanced required, or will standard TIA Portal work?

Failsafe modules in the ET 200SP family, including the 6ES7136-6BA00-0CA0, require the SIMATIC STEP 7 Safety Advanced software option within TIA Portal v12 or later. Standard TIA Portal without the Safety Advanced license can detect the module in the hardware configuration but cannot configure its failsafe parameters, download a safety program, or validate safety-relevant settings. Confirm your license tier before beginning hardware configuration.

What certifications does this module carry for international projects?

The 6ES7136-6BA00-0CA0 holds EU Declaration of Conformity, UK Declaration of Conformity, UL, CCC, KC, and EAC approvals, as well as maritime certifications from DNV, ABS, and Lloyd's Register. It is also RoHS compliant. This breadth of certification makes it suitable for projects in North America, Europe, Asia, and offshore/marine applications without sourcing country-specific variants.

What is the cable length limit for input signal wiring?

The module supports input cable lengths of up to 1000 m using shielded twisted-pair cable and up to 500 m using unshielded cable. For runs approaching these limits, verify that the voltage drop along the cable does not cause the received signal voltage to fall outside the valid "1" range of +15 to +30 V at the module input terminal. Shielded cable is strongly recommended for runs in electrically noisy environments such as motor drive enclosures or high-current power distribution panels.

How does the PL E / SIL 3 rating affect my safety circuit design documentation?

PL E (ISO 13849-1) and SIL 3 (IEC 61508) are the module's certified safety integrity levels for use in a properly designed safety function. The module's probability of dangerous failure on demand over a 20-year service life is documented at less than 2.00E-05, and in high-demand mode the probability of dangerous failure per hour is less than 1.00E-09. These figures are inputs to your safety function calculation (SISTEMA or equivalent tool). The module comes with a Type Examination Certificate and supports CE marking under the Machinery Directive (2006/42/EC), which simplifies the compliance documentation package for machinery sold into regulated markets.

Why Order From LeadTime.ca

  • LeadTime.ca ships the 6ES7136-6BA00-0CA0 and other SIMATIC ET 200SP modules worldwide — no regional restrictions on sourcing or quoting.
  • Specialists can confirm module compatibility, base unit type, and STEP 7 version requirements before you commit to a purchase order.
  • Volume pricing is available for multi-module orders; contact the team directly for project-level quotes on safety I/O builds.
  • Hard-to-find variants and current-firmware stock are sourced through verified supply channels — call out firmware version V2.0 when requesting a quote to confirm you receive the current revision.
  • View current pricing and stock for the 6ES7136-6BA00-0CA0 at LeadTime.ca
  • Contact LeadTime.ca for a project quote or lead time confirmation

At-a-Glance Summary

  • Catalog number: Siemens 6ES7136-6BA00-0CA0 — F-DI 8x 24 V DC HF module for SIMATIC ET 200SP
  • 8 failsafe digital inputs at 24 V DC; signal "1" range +15 to +30 V
  • 8 encoder supply outputs at 24 V DC; 0.3 A per channel, 800 mA total maximum
  • Safety certifications: PL E (ISO 13849-1), SIL 3 (IEC 61508); probability of dangerous failure per hour less than 1.00E-09 (high demand)
  • Module dimensions: 15 mm wide × 73 mm high × 58 mm deep; weight 49 g
  • Backplane power consumption: 70 mW; compatible with BU type A0 base units only
  • Cable length: 1000 m shielded, 500 m unshielded
  • Operating temperature: 0 to 60°C horizontal, 0 to 50°C vertical; maximum altitude 4000 m
  • Engineering software: STEP 7 TIA Portal v12 or later (Safety Advanced license required); STEP 7 v5.5 SP3 or later
  • Certifications: UL, CCC, KC, EAC, DNV, ABS, Lloyd's Register, EU and UK Declaration of Conformity, RoHS
  • Design life: 20 years; firmware version V2.0 current; classified as spare part (not obsolete) in Siemens catalog