Siemens APOGEE CCM+ Modules: QLCCM24AAN 16418-41

Technical Dossier

Product Details And Specifications

Siemens APOGEE CCM+ Series: Comprehensive Module Range and Technical Overview

The Siemens APOGEE CCM+ (Critical Control Module Plus) series represents a dedicated line of direct digital control (DDC) field-level controllers deployed across heavy industrial and commercial building automation infrastructure worldwide. These modules are embedded in HVAC control systems, critical process environments, and facility management networks in chemical plants, pharmaceutical manufacturing facilities, power generation stations, and large-scale commercial campuses. The CCM+ platform operates within the Siemens APOGEE Building Automation System (BAS) ecosystem, interfacing with field panels, terminal equipment controllers, and supervisory workstations via P1/P2 bus and BACnet/IP communication layers. The QLCCM24AAN 16418-41 is a 24 VAC-powered variant of the CCM+ controller, designed for critical control loops requiring high-reliability analog and digital I/O management.

The Evolution of CCM+ Architecture

The APOGEE CCM+ series succeeded the earlier CCM (Critical Control Module) generation, which was introduced in the 1990s as part of Siemens' APOGEE field panel ecosystem. The original CCM used proprietary P1 bus communication and supported a fixed I/O count with limited expansion capability. The CCM+ generation introduced modular I/O expansion, enhanced onboard processing, and dual-port P2 bus support, enabling peer-to-peer communication between field panels without supervisory intervention.

Key architectural transitions across the CCM+ lifecycle include the shift from EEPROM-based firmware storage to flash memory (enabling field firmware updates), the introduction of BACnet MS/TP native support alongside the legacy P1/P2 bus, and the integration of onboard PID loop execution with anti-windup and feed-forward compensation. Later CCM+ variants added Ethernet/IP gateway capability, allowing direct integration with enterprise-level SCADA and EMS platforms. The series has entered its mature/end-of-active-production phase; Siemens has transitioned new installations toward the APOGEE PXC series (PXC36, PXC64, PXC100, PXC200) and the Desigo CC platform. However, the CCM+ remains in active service across thousands of installed base sites, making long-term spare parts availability a critical operational requirement.

CCM+ Full Catalog & Functionalities (SKU List)

Controllers / CPU Modules

• QLCCM24AAN 16418-41: 24 VAC CCM+ Critical Control Module Plus, standalone DDC controller, P2 bus, onboard I/O
• QLCCM24AAN 16418-40: 24 VAC CCM+ prior revision, compatible firmware base, P1/P2 dual bus
• QLCCM24AAN 16418-42: 24 VAC CCM+ updated revision with enhanced flash memory capacity
• QLCCM120AAN: 120 VAC-powered CCM+ variant for North American line-voltage panel installations
• QLCCM230AAN: 230 VAC CCM+ variant for European and international voltage standards

Analog Input / Output Modules

• QLAIX8: 8-channel universal analog input expansion module, 0–10 VDC / 4–20 mA / RTD selectable
• QLAOX4: 4-channel analog output module, 0–10 VDC, for valve actuator and damper control
• QLAOX8: 8-channel analog output expansion, supports proportional control loops
• QLAIXT8: 8-channel analog input with onboard signal conditioning for thermistor inputs

Digital Input / Output Modules

• QLDIX16: 16-channel digital input module, dry contact, 24 VAC/VDC compatible
• QLDOX8: 8-channel digital output module, triac outputs, 24 VAC load switching
• QLDOX16: 16-channel digital output expansion, relay or triac output selectable
• QLDIX8: 8-channel digital input, status monitoring for binary field devices

Communication & Network Modules

• QLBNI: BACnet network interface module, MS/TP to Ethernet gateway for CCM+ field panels
• QLP2T: P2 bus trunk repeater/isolator, extends P2 bus segment length and provides electrical isolation
• QLLAN: Local area network interface card for APOGEE supervisory workstation connectivity

Power Supply Modules

• QLPS24: 24 VAC/VDC regulated power supply module for CCM+ panel bus
• QLPSX: Extended-capacity power supply for high I/O count CCM+ panel configurations

Sourcing Hard-to-Find & Obsolete CCM+ Parts

The CCM+ series has been formally discontinued from Siemens' active production catalog. Standard Siemens distribution channels no longer carry new-manufacture stock for the majority of CCM+ module variants. DriveKNMS maintains a dedicated inventory of new-surplus, refurbished, and tested-used CCM+ modules sourced from decommissioned plant equipment, authorized liquidation channels, and long-term warehousing programs.

For end-users operating APOGEE CCM+ installations with a remaining service life of 5–15 years, DriveKNMS provides lifecycle extension support including: direct module replacement with functionally equivalent tested units, firmware version matching to ensure compatibility with existing panel configurations, and cross-reference advisory for identifying compatible substitute modules where direct replacements are unavailable. All sourced units are documented with traceability records covering origin, inspection history, and test results prior to shipment.

Quality Control for the CCM+ Range

CCM+ modules present specific quality verification challenges due to their integrated backplane bus architecture and multi-protocol communication stack. DriveKNMS applies a structured test protocol to all CCM+ units prior to dispatch:

• Power-on functional test: Module is energized at rated voltage (24 VAC / 120 VAC / 230 VAC per variant) and boot sequence is verified against known-good firmware initialization signatures.
• P1/P2 bus communication test: Module is connected to a reference APOGEE field panel and polled via Siemens APOGEE Terminal Service to confirm address assignment, object enumeration, and command response.
• I/O channel verification: Each analog input channel is stimulated with calibrated signals (0–10 VDC, 4–20 mA, RTD simulation) and output values are verified against specification tolerances. Digital I/O channels are cycled and state changes confirmed.
• Backplane connector inspection: Edge connectors and backplane bus contacts are inspected under magnification for oxidation, mechanical damage, and pin alignment. Contacts are cleaned and treated where required.
• Thermal soak test: Units are operated at elevated ambient temperature (50°C) for a minimum of 4 hours to screen for latent component failures.
• Firmware version documentation: Installed firmware revision is recorded and provided with the unit to allow the end-user to assess compatibility with their existing panel software version.