Siemens LOGO! 8.3 Logic Module: AWS Cloud Integration Guide

1. LOGO! 8.3 Series Overview

The Siemens LOGO! 8.3 logic module series (order number root 6ED1052-XXX08-0BA1) is the third generation of the LOGO! 8 platform, distinguished from prior LOGO! 8.0/8.1/8.2 hardware by integrated direct cloud connectivity. The 8.3 release targets small automation applications where a separate IoT gateway would otherwise be required to bridge the controller to a cloud broker. The compact logic module retains the integrated display, on-board digital and analog I/O, Ethernet interface, and modular expansion capability of the LOGO! 8 family while adding a TLS-secured MQTT client that publishes to Amazon Web Services (AWS) IoT Core.

The 8.3 device family is documented in the LOGO! 8.3 Operating Instructions, Edition 10/2020, and is supported by LOGO! Soft Comfort (LSC) V8.3 and the LOGO! Web Editor V1.1. The hardware identification suffix -0BA1 differentiates the 8.3 generation from earlier 8.2 stock-keeping units ending in -0BA0. Order numbers are activated in the Siemens Industry Mall, and product delivery was scheduled for end of October 2020.

Reference: Siemens LOGO! Basic Modules product page.

2. Hardware Variants and Order Number Structure

The LOGO! 8.3 family follows the established Siemens 6ED1052 catalog root. The variant digits in positions 5–7 (XXX) define display, I/O count, voltage, and output type. The example SKU 6ED1052-1MD08-0BA1 decodes as follows:

Compared with the equivalent 8.2 SKU 6ED1052-1MD08-0BA0, the trailing two-character change (0BA0 → 0BA1) is the only external differentiator. Field engineers must inspect the device label to confirm the 8.3 generation before commissioning cloud features; 8.2 hardware does not support the integrated AWS MQTT client.

3. LOGO! Soft Comfort V8.3 Programming Environment

LOGO! Soft Comfort (LSC) V8.3 is the engineering software for the 8.3 generation. Prior to the V8.3 release, LSC V8.2.1 (also marketed as 8.2 SP1) was the most current available version. V8.3 introduces the cloud connection configuration editor, certificate provisioning workflow, and updated project templates for the 8.3 device family.

LSC V8.3 commissioning steps for cloud activation:

1. Open or create the LOGO! program in LSC V8.3.
2. Select Tools → Cloud Connection (menu path confirmed in the LOGO! 8.3 manual, Edition 10/2020).
3. Generate a Certificate Signing Request (CSR) for the LOGO! device; LSC submits the CSR to AWS IoT Core.
4. Import the AWS-issued device (client) certificate and root CA chain into the LSC project.
5. Download the completed program to the LOGO! 8.3 module via Ethernet.
6. Verify cloud link status on the LOGO! onboard display or in the LSC online diagnostics.

Reference: LOGO! 8 Product Overview (DigiKey PDF).

4. LOGO! Web Editor V1.1

The LOGO! Web Editor V1.1 is the companion tool for building custom HTML5 dashboards that run on the LOGO! onboard web server. V1.1, documented in the Web Editor Online Help Edition 10/2020, is bundled with LSC V8.3 and supports the 8.3 device generation. The web editor allows engineers to drag variable tags, status indicators, and input widgets onto a browser-based visualization served directly by the LOGO! module.

For applications that require both local browser-based HMI and cloud telemetry, deploy a separate LOGO! 8.2 module (with active web server) and a LOGO! 8.3 module (with active cloud link) on the same Ethernet segment, or front-end the 8.3 cloud with a local MQTT broker that mirrors the data to a local dashboard.

5. Cloud Connectivity Architecture

The LOGO! 8.3 cloud feature implements a standard MQTT 3.1.1 client with mutual TLS (mTLS) authentication against AWS IoT Core. The architecture is intentionally constrained to AWS because the device certificate provisioning workflow is tightly coupled with AWS IoT certificate authority issuance. The cloud endpoint, certificate authority, and device policy are not user-configurable in the 8.3 firmware release.

The MQTT server is not configurable in the 8.3 firmware; engineers cannot redirect the cloud link to a private broker, an on-premises Mosquitto instance, or a non-AWS managed MQTT service without modifying the device firmware. The standard MQTT protocol on the wire would technically allow such a configuration, but the certificate chain validation against the AWS CA prevents a redirect at the TLS handshake.

6. mTLS Security Implementation

Mutual TLS is the security model for the LOGO! 8.3 → AWS IoT Core link. The certificate flow is:

1. Key pair generation: LSC V8.3 generates an RSA key pair on the engineering PC and a corresponding Certificate Signing Request (CSR) containing the public key and device identifier.
2. CSR submission to AWS: The CSR is submitted to AWS IoT Core, which issues a device (client) X.509 certificate signed by the AWS IoT certificate authority.
3. Certificate download: The signed certificate, the AWS root CA certificate, and any intermediate CA certificates are downloaded from AWS and imported into the LSC V8.3 project.
4. Provisioning to LOGO!: The complete certificate chain and private key are downloaded to the LOGO! 8.3 module along with the program.
5. TLS handshake: At runtime, the LOGO! 8.3 initiates a TLS 1.2 connection to the AWS IoT endpoint. The AWS server presents its certificate chain; the LOGO! 8.3 client presents its device certificate. Both sides validate against their respective trust stores.
6. MQTT session: Upon successful mTLS handshake, the LOGO! 8.3 establishes an MQTT session and begins publishing process data.

Because the device certificate is provisioned per device, certificate rotation requires re-provisioning via LSC V8.3. There is no ACME, EST, or SCEP-based automated enrollment in the 8.3 release; PKI is "hard-coded" into the device firmware in the sense that the trust anchor is the AWS IoT CA.

7. Compatibility and Migration from LOGO! 8.2

Engineers maintaining installed bases of LOGO! 8.2 modules should treat 8.3 as a parallel product line, not a drop-in firmware upgrade. The hardware differences are substantial enough that the 8.3 communication stack is not backported to 8.2 modules.

Existing LSC V8.2 projects can be opened in LSC V8.3 and downloaded to 8.3 hardware, but the cloud activation is an additional configuration step that must be added to the project. Conversely, a project downloaded to a LOGO! 8.2 module cannot be "upgraded" to add cloud features by re-targeting it to 8.3 hardware; the project must be opened in LSC V8.3 and the cloud block enabled.

8. Commissioning Procedure

The following procedure activates the AWS cloud link on a LOGO! 8.3 module. Prerequisites are an AWS account with IoT Core activated, LSC V8.3 installed, and the LOGO! 8.3 module reachable on Ethernet from the engineering PC.

1. Configure AWS IoT Core: In the AWS Management Console, navigate to IoT Core and create a policy that grants the LOGO! device permission to connect, publish, and subscribe on its assigned topics.
2. Register a thing: Register the LOGO! 8.3 as a "thing" in the AWS IoT registry. Note the AWS IoT endpoint URL (format xxxxxxxxxxxx-ats.iot.<region>.amazonaws.com) for reference.
3. Generate CSR in LSC: In LSC V8.3, open the project, select Tools → Cloud Connection → Generate CSR, and save the CSR file.
4. Create AWS IoT certificate: In AWS IoT Core, select Secure → Certificates → Create → Use CSR, upload the CSR, and activate the certificate. Attach the policy from step 1 and the thing from step 2 to the certificate.
5. Download certificates: Download the device certificate, the private key (generated when the CSR was created), and the Amazon Root CA 1 certificate from AWS.
6. Import into LSC: In LSC V8.3, select Cloud Connection → Import Certificates and load the three PEM files.
7. Configure publish topic: In the LSC cloud editor, define the MQTT topic(s) the LOGO! 8.3 will publish to and the variable tags to include in each payload.
8. Download to LOGO!: Transfer the program and certificates to the LOGO! 8.3 via Ethernet. Confirm the transfer completes without certificate errors.
9. Verify link: In AWS IoT Core, open the Test → MQTT test client, subscribe to the LOGO! topic, and confirm messages are received. Alternatively, observe the LOGO! onboard display for the cloud connection status icon.

9. Operational Constraints and Limitations

Several constraints shape how the LOGO! 8.3 cloud feature can be deployed in production:

• AWS-only broker: The 8.3 firmware rejects connections to non-AWS endpoints. Local brokers, Azure IoT Hub, Google Cloud IoT, and generic Mosquitto/HiveMQ servers are not supported.
• No web server with cloud: The internal web server is disabled while the cloud client is active. If local browser visualization is required, deploy a separate 8.2 module or use a downstream broker that serves a local dashboard.
• No configurable MQTT server: The broker address, CA trust anchor, and authentication policy are not editable in the user interface.
• Manual certificate rotation: Certificate renewal requires re-provisioning via LSC V8.3. There is no automated certificate lifecycle management in the 8.3 release.
• Single MQTT client: The LOGO! 8.3 acts as an MQTT client only; it cannot host an MQTT broker for downstream devices.
• Publish bandwidth: The LOGO! 8.3 processor is resource-constrained. Publish intervals below 1 second across many tags may starve the ladder scan. Plan tag counts and publish rates to keep CPU utilization under 70%.

For applications requiring a non-AWS broker, the standard MQTT protocol on the wire suggests the configuration is technically feasible, but it would require a custom firmware modification, breaking Siemens support and warranty.

10. Troubleshooting Matrix

11. Field-Proven Design Notes

Three design patterns are emerging for LOGO! 8.3 deployments:

1. Single-module direct cloud: The LOGO! 8.3 publishes directly to AWS IoT Core. Local HMI is sacrificed. Best for retrofits where remote telemetry is the primary requirement and no local visualization is needed.
2. Two-module split architecture: A LOGO! 8.2 module handles the local web visualization; a LOGO! 8.3 module reads the same process signals and publishes to AWS. The two modules share the sensor wiring and communicate over Modbus TCP. Best when both local and remote visibility are required.
3. Gateway-fronted cloud: A third-party IoT gateway (or a Siemens SIMATIC IoT2050) sits between one or more LOGO! 8.2 controllers and AWS. Use this when the application already has a gateway and the LOGO! 8.3 cloud feature is not required.

For new installations, the single-module direct cloud pattern is the most cost-effective because it eliminates the dedicated gateway hardware. For installations with an existing LOGO! 8.2 installed base, the two-module split is typically the lowest-risk migration path.

12. Frequently Asked Questions