Siemens 6ES7138-6AA01-0BA0 — ET 200SP Counter Module Buyer Guide

By Abdullah Zahid
12 min read
Siemens 6ES7138-6AA01-0BA0 SIMATIC ET 200SP TM Count 1x24V counter module for incremental encoder measurement

Siemens 6ES7138-6AA01-0BA0 SIMATIC ET 200SP TM Count 1x24V Counter Module: Specifications, Compatibility, and Integration Guide

Controls engineers specifying encoder measurement for SIMATIC ET 200SP systems frequently arrive at the Siemens 6ES7138-6AA01-0BA0 after ruling out PLC-based counting as too scan-cycle-dependent for their application. This module — the SIMATIC ET 200SP TM Count 1x24V — is a single-channel 24V incremental encoder counter that mounts directly in an ET 200SP BaseUnit type A0, delivers up to 100 ppm measurement accuracy at firmware V2.0, and includes 3 digital inputs and 2 digital outputs for control signaling without adding external hardware to the panel.

If you have already confirmed this is the correct part for your ET 200SP system, check current pricing and availability for the Siemens 6ES7138-6AA01-0BA0 at LeadTime.ca — ships worldwide.

Who Should Buy the Siemens 6ES7138-6AA01-0BA0 — and Who Shouldn't

The 6ES7138-6AA01-0BA0 is the right choice for engineers who need high-precision pulse counting or incremental encoder measurement integrated natively into an existing SIMATIC ET 200SP distributed I/O system. You are the target buyer if all of the following apply:

  • Your host system is SIMATIC ET 200SP and your slot is a BaseUnit type A0 — not type A2, B, C, or U
  • Your encoder or pulse sensor produces a 24V DC output signal — not 5V TTL and not 48V
  • Your application requires only one counting channel per module position
  • Your control CPU is an S7-1200 or S7-1500 with current firmware supporting ET 200SP technology modules
  • You need isochronous mode operation for motion control synchronization or deterministic timing
  • You are configuring through TIA Portal and need technology object mode, manual operation mode, or fast mode support

If your encoder outputs 5V TTL or 48V, if you need more than one counting channel from a single module position, or if your distributed I/O platform is anything other than SIMATIC ET 200SP (including ET 200M or ET 200eco), this module is mechanically and electrically incompatible. Select an alternative technology module suited to your voltage class and platform.

On this page:

What the Siemens 6ES7138-6AA01-0BA0 Actually Does in a Running System

The SIMATIC ET 200SP TM Count 1x24V is a technology module — a category distinct from standard digital I/O within the ET 200SP family. Where a standard DI module simply reads a signal state, the 6ES7138-6AA01-0BA0 captures and accumulates pulse trains from 24V incremental encoders or pulse-generating sensors with up to 100 ppm measurement accuracy, a level of precision that PLC scan-cycle counting cannot consistently achieve in high-frequency applications.

The module offloads all counting logic from the main S7-1200 or S7-1500 CPU. Rather than consuming CPU scan time on interrupt-driven counter routines, the host PLC simply reads or writes to the module's address space and technology object. This separation is what makes the 6ES7138-6AA01-0BA0 appropriate for motion control, position tracking, and throughput metering applications where determinism matters — particularly when isochronous mode is activated for synchronized multi-axis timing.

Three digital inputs and two digital outputs are integrated into the module, handling start/stop commands, mode selection, alarm monitoring, and external device control at 24V logic levels — all without additional wiring modules. Firmware V2.0 ships as the current production standard and is also updateable via TIA Portal for modules already in the field. The single-unit article number is 6ES7138-6AA01-0BA0; volume buyers can order the 10-pack under article number 6ES7138-6AA01-2BA0.

Where the 6ES7138-6AA01-0BA0 Sits in Your ET 200SP System Architecture

This module occupies a plug-in slot in an ET 200SP BaseUnit type A0, positioned downstream of the ET 200SP interface module that handles communication back to the controlling CPU. It receives 24V encoder pulses at the field level and presents structured count data upward through the ET 200SP backplane to the PLC.

  • S7-1200 or S7-1500 CPU — communicates with ET 200SP via PROFINET or PROFIBUS through the interface module
  • ET 200SP Interface Module (IM) — manages data exchange between CPU and all downstream modules on the ET 200SP station
  • ET 200SP BaseUnit type A0 — provides the mechanical housing, 24V power rail, and connector interface for the 6ES7138-6AA01-0BA0
  • Siemens 6ES7138-6AA01-0BA0 TM Count 1x24V — captures 24V incremental encoder pulses, integrates 3 DI and 2 DQ, surfaces count data to CPU address space
  • 24V incremental encoder or pulse sensor — field device generating phase A, phase B, and optional Z index pulse signals at 24V output level

Industries and Machine Types Where This Counter Module Is Commonly Deployed

Packaging machinery is among the most common deployment environments for the 6ES7138-6AA01-0BA0. The module counts incremental pulses from servo motor encoders to track carton or product position, triggering label applicators or fill heads at precise position setpoints. Isochronous mode ensures timing remains synchronized with other machine axes running from the same S7-1500 motion CPU.

Conveyor and material handling systems use the module to count pulse outputs from load cell amplifiers or proximity sensors, measuring product throughput in real time. The two integrated digital outputs can directly trigger diverter gates or solenoid valves at accurate count intervals without routing signals back through the main PLC output card.

Automated storage and retrieval (AS/RS) systems and robotic positioning applications rely on the 6ES7138-6AA01-0BA0 for homing and limit detection. The module generates a count interrupt to the S7-1200 or S7-1500 CPU when an encoder reaches a defined setpoint, triggering the next move sequence without adding latency through the main scan cycle.

Speed monitoring and fault detection on motor-driven equipment — including spindles, pumps, and conveyors — is another validated use case. Pulse frequency analysis within the module detects stalled shafts (low pulse frequency) or overspeed conditions and reports them to the CPU for alarm handling.

Multi-axis synchronization in filling, palletizing, and printing applications leverages isochronous mode to ensure the counter module's timing is phase-locked with the main motion control axis, delivering jitter-free coordination between machine functions.

Application Typical Deployment
Packaging Machinery Servo encoder feedback for carton position tracking; label applicator trigger at position setpoint
Conveyor and Material Handling Pulse counting from proximity or load cell sensor for throughput metering; DQ triggers diverter gate
AS/RS and Robotics Homing and limit detection via encoder interrupt; feeds next-move trigger to S7-1500 CPU
Motor Speed Monitoring Pulse frequency analysis for stall detection and overspeed alarm on spindle or pump
Multi-Axis Synchronization Isochronous mode counter on ET 200SP coordinated with main motion CPU for filling or palletizing
Food and Beverage / Pharma Production rate metering and batch counting on fill or dose lines requiring accurate count records

Key Specifications Every Engineer Needs Before Ordering

Parameter Value / Description
Module Type TM Count 1x24V Technology Module
Article Number 6ES7138-6AA01-0BA0 (single) / 6ES7138-6AA01-2BA0 (pack of 10)
Firmware Version V2.0 (updateable via TIA Portal)
Encoder Input Channels 1 x 24V DC incremental encoder input
Digital Inputs 3 DI at 24V logic level
Digital Outputs 2 DQ at 24V logic level
Measurement Accuracy Up to 100 ppm
Compatible Base Unit ET 200SP BaseUnit type A0 only (not A2, B, C, or U)
Control CPU Compatibility S7-1200, S7-1500 with current firmware
Operating Modes Technology object mode, manual operation mode, fast mode, isochronous mode

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

6ES7138-6AA01-0BA0 vs. 6ES7138-6AA00-0BA0 and Related Alternatives

Module Key Difference / Relationship
6ES7138-6AA01-0BA0 (V2.0) Current generation; firmware V2.0; fully compatible replacement for V1.x predecessor
6ES7138-6AA00-0BA0 (V1.x) Previous generation; firmware and hardware improvements carried into V2.0; discontinued for new designs
6ES7138-6AA01-2BA0 Same module; 10-pack packaging for OEM and volume system integrator orders
ET 200SP Standard DI/DO Modules Fixed digital I/O only; no counting function; cannot replace technology module role
External Pulse Counter Hardware Requires separate enclosure and additional wiring; no native CPU integration; increases panel footprint

For new system designs and retrofit upgrades, the 6ES7138-6AA01-0BA0 at firmware V2.0 is the correct current specification. If your architecture calls for volume ordering, check current availability for both the single-unit and 10-pack options at LeadTime.ca.

Expert Verdict: Is This the Right Counter Module for Your Application?

The Siemens 6ES7138-6AA01-0BA0 earns its place in ET 200SP-based machine architectures by solving a real engineering problem: high-frequency pulse counting without consuming CPU scan time or adding external hardware. The 100 ppm measurement accuracy at firmware V2.0 exceeds what most encoder measurement applications require, and the four operating modes — including isochronous mode — make this module usable across a wide spectrum from simple throughput metering to synchronized motion control. The integrated 3 DI and 2 DQ channels eliminate what would otherwise be a separate I/O module for control signaling, which saves both slot space and wiring labor.

The honest limits of this module are equally clear. Single-channel architecture means that an application with two or more encoders requires either parallel module installations or a different approach — the 6ES7138-6AA01-0BA0 does not expand to multi-channel within a single slot. The fixed 24V input voltage is a hard constraint; if your encoder outputs 5V TTL or 48V, no firmware or configuration workaround changes the hardware input stage. And the mechanical requirement for a BaseUnit type A0 is absolute — if your panel is equipped with type A2, B, C, or U base units, this module cannot be installed without replacing the base unit itself.

From a procurement standpoint, the 6ES7138-6AA01-0BA0 is listed as an active product with no announced discontinuation. Lead times typically range from 2 to 12 weeks depending on stock levels and order volume. Volume buyers ordering 10 or more units should evaluate the 6ES7138-6AA01-2BA0 10-pack for per-unit cost efficiency. If this module matches your system requirements, view current stock and pricing at LeadTime.ca — we ship 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 for the TM Count 1x24V

  • Verify the host ET 200SP BaseUnit is type A0 before attempting module insertion — mechanical keying prevents insertion into incompatible base unit types, but forced insertion risks connector damage
  • Confirm the 24V DC supply to the ET 200SP base unit is stable before module power-up; the 6ES7138-6AA01-0BA0 draws all power from the BaseUnit 24V rail and has no separate power connector
  • Connect the 24V incremental encoder's phase A, phase B, and optional Z index outputs to the corresponding terminals on the BaseUnit connector per the pinout diagram in the official Siemens manual (Section 3: Wiring); use shielded twisted pair cable and verify signal voltage is 24V before connection
  • The 3 digital inputs can be wired for start/stop commands, mode selection, or alarm monitoring at 24V logic; the 2 digital outputs support external indicator lamps, solenoid valves, or enable/disable control at 24V logic
  • In TIA Portal, add the TM Count 1x24V to the ET 200SP hardware configuration, assign I/O addresses for DI and DQ channels, select operating mode (technology object mode recommended for motion control applications), and download to the CPU before verifying count register behavior in the watch table

Compatible Modules and System Expansion Within ET 200SP

The 6ES7138-6AA01-0BA0 operates within the SIMATIC ET 200SP distributed I/O station alongside other ET 200SP modules sharing the same base unit rail and interface module. The following module types are relevant when expanding or completing an ET 200SP station that includes the TM Count 1x24V:

  • ET 200SP Interface Module (IM) — required for PROFINET or PROFIBUS communication between the ET 200SP station and the S7-1200 or S7-1500 CPU; the IM must support technology modules
  • ET 200SP BaseUnit type A0 — the specific mechanical housing required for the 6ES7138-6AA01-0BA0; provides the 24V power rail and signal connector interface
  • ET 200SP Standard Digital I/O Modules — can be mixed in the same station for conventional on/off I/O requirements alongside the counter technology module
  • Additional 6ES7138-6AA01-0BA0 modules — for multi-encoder applications, install one module per counting channel, each in its own type A0 base unit slot within the same ET 200SP station
  • 6ES7138-6AA01-2BA0 (10-pack) — volume packaging of the same module for OEM builds or multi-station projects

Wrong-Part Prevention: Run This Checklist Before You Purchase

Before submitting a purchase order for the Siemens 6ES7138-6AA01-0BA0, confirm every item on this checklist. These are the most common sources of incompatibility and mis-shipment in the field:

  1. Verify host system is SIMATIC ET 200SP; this module does not work with other Siemens distributed I/O families (SIMATIC ET 200M, ET 200eco, etc.)
  2. Confirm BaseUnit type is A0; other base unit types (type A2, B, C, U) are mechanically incompatible
  3. Check encoder/sensor output voltage is 24V; module will not function with 5V TTL or 48V sensor signals
  4. Verify power supply for the module is 24V DC (derived from ET 200SP 24V rail); do not assume module is powered from PLC logic supply
  5. Confirm firmware version V2.0 is compatible with your TIA Portal version; earlier firmware (V1.x) may require updates
  6. Ensure control CPU (S7-1200, S7-1500, KTP mobile panel) has current firmware supporting ET 200SP technology modules
  7. Validate that your application requires only 1 counting channel; multi-encoder systems need parallel modules or alternative solution
  8. Check lead time for 1-piece order (6ES7138-6AA01-0BA0) vs. 10-piece bundle (6ES7138-6AA01-2BA0) and plan procurement accordingly

If every item above is confirmed, proceed to the product page at LeadTime.ca to check stock and request a quote — or contact our team if you need to validate a line item before issuing your PO.

Frequently Asked Questions

Is the 6ES7138-6AA01-0BA0 a direct plug-and-play replacement for the 6ES7138-6AA00-0BA0?

Yes. The 6ES7138-6AA01-0BA0 with firmware V2.0 is the stated fully compatible replacement for the older 6ES7138-6AA00-0BA0 (V1.x). It is mechanically, electrically, and software compatible with existing ET 200SP type A0 base units and TIA Portal configurations. New system designs should specify the current 6ES7138-6AA01-0BA0, and retrofit installations can substitute it directly. Verify your TIA Portal version supports V2.0 firmware before proceeding with a retrofit.

Can I connect a 5V TTL encoder to the 6ES7138-6AA01-0BA0?

No. The encoder input channel is fixed at 24V DC. Connecting a 5V TTL encoder output will result in no signal recognition or incorrect counting due to voltage level mismatch — the input stage does not auto-detect or adapt to lower signal levels. If your encoder outputs 5V TTL, you require either a signal converter to step up to 24V or a different technology module rated for 5V inputs. Confirm encoder output voltage from the sensor datasheet before wiring.

Does the 6ES7138-6AA01-0BA0 include protection breakers or overcurrent devices?

No. External protection devices are required for the module — protection is not integrated within the 6ES7138-6AA01-0BA0 itself. Plan for appropriate 24V rail protection in your ET 200SP panel design per Siemens wiring standards and applicable local electrical codes.

What happens if I need to count more than one encoder in the same ET 200SP station?

The 6ES7138-6AA01-0BA0 supports a single counting channel per module. For multi-encoder applications, install one module per encoder, each in its own ET 200SP BaseUnit type A0 slot within the same station. Each module will appear as a separate technology object or address block in TIA Portal. Alternatively, evaluate whether a different architecture — such as parallel ET 200SP stations — better suits your wiring and slot budget.

What TIA Portal version is required for the 6ES7138-6AA01-0BA0 at firmware V2.0?

The module requires a TIA Portal version that supports ET 200SP technology modules at firmware V2.0. Siemens documents the specific minimum TIA Portal version in the module manual and hardware catalog entry. If you are running an older TIA Portal release, verify compatibility before committing to a firmware V2.0 installation. Earlier firmware V1.x may be usable with older TIA Portal versions but lacks the improvements included in V2.0.

What is the typical lead time for the 6ES7138-6AA01-0BA0 and is volume pricing available?

Lead time for the 6ES7138-6AA01-0BA0 typically ranges from 2 to 12 weeks depending on distributor stock levels and regional demand at time of order. The 6ES7138-6AA01-2BA0 10-pack is available for volume buyers and typically offers a lower per-unit cost. LeadTime.ca ships worldwide — contact our team for a current lead time confirmation and volume pricing before issuing your purchase order.

Why Order the 6ES7138-6AA01-0BA0 From LeadTime.ca

  • LeadTime.ca ships the Siemens 6ES7138-6AA01-0BA0 worldwide — no geographic restriction on orders
  • Both single-unit (6ES7138-6AA01-0BA0) and 10-pack (6ES7138-6AA01-2BA0) options available; contact for volume pricing on larger quantities
  • Sourcing support for hard-to-find or long-lead SIMATIC ET 200SP technology modules — contact our team before delays affect your build schedule
  • Response time focused on procurement specialists and controls engineers who need price and availability confirmed before PO release
  • EAN 4047623410607 / UPC 804766953903 — quote by part number for clean procurement documentation

At-a-Glance Summary

  • Article number: 6ES7138-6AA01-0BA0 (single unit) / 6ES7138-6AA01-2BA0 (pack of 10)
  • Official product name: SIMATIC ET 200SP TM Count 1x24V Counter Module
  • Firmware version: V2.0 — updateable via TIA Portal; fully compatible replacement for 6ES7138-6AA00-0BA0 (V1.x)
  • Single-channel 24V DC incremental encoder input — not compatible with 5V TTL or 48V signals
  • 3 digital inputs and 2 digital outputs at 24V logic — integrated, no additional I/O module required
  • Measurement accuracy: up to 100 ppm
  • Compatible base unit: ET 200SP BaseUnit type A0 only — type A2, B, C, and U are incompatible
  • Control CPU compatibility: S7-1200 and S7-1500 with current firmware
  • Operating modes: technology object mode, manual operation mode, fast mode, isochronous mode
  • Power source: 24V DC via ET 200SP BaseUnit rail — no separate module power connector
  • Life cycle status: Active Product — EAN 4047623410607 / UPC 804766953903
  • Typical lead time: 2 to 12 weeks depending on stock; confirm with LeadTime.ca before build commitment