Siemens PXC5.E24.A

Building automation controller

Siemens documents PXC5.E24.A, order number S55375-C120, as a 24-point modular automation station supporting BACnet/IP, BACnet/SC and BACnet MS/TP. Its current PICS supports BACnet read-property services and common input and value objects. That establishes controller capability, but not an Edge BACnet/SC path, a minimum installed firmware, project object identifiers or permission to read or command them. Direct Edge monitoring remains unverified until the installed transport, firmware, PICS, commissioned object export and a read-only pilot are accepted.

  • BACnet/IP
  • BACnet/SC
  • BACnet MS/TP
  • Modbus RTU

Building automation controller

Compatibility

Direct Edge integration not yet verified

Siemens publishes exact-model BACnet transports, BACnet device profiles, read-property services and supported object types. The retained sources do not prove that an installed Edge build supports the selected transport, especially BACnet/SC, or provide the installed firmware and commissioned object identities. BACnet/SC capability on the controller must not be treated as BACnet/IP compatibility in Edge.

PXC5.E24.A S55375-C120 only. Record firmware, DT+ and ABT Site project versions, active transport, BACnet device instance and current PICS. Obtain the commissioned object export. A proposed Edge client must be read-only and use the approved BACnet/IP network if and only if the installed Edge build supports it. BACnet/SC and MS/TP require separate proven client paths. Do not write Present_Value, priority arrays, schedules, alarms, parameters, PPCL logic or outputs.

Models

Download
ModelsInterfaceRoute into Edge
PXC5.E24.A, S55375-C12024 onboard I/O, up to six TX-I/O modules, three Ethernet ports and two configurable EIA-485 field-level interfaces.Hold a direct route until firmware, active BACnet transport, current PICS, device instance, commissioned object export and Edge client support are proven.
PXC5.E24-N.A, S55375-C131No-WLAN hardware variant with its own order number.Treat it as a distinct hardware identity even where BACnet functions are shared.
Earlier PXC5.E24 and other PXC4, PXC5 or PXC7 controllersSeparate order codes, hardware generations, datasheets and capacity limits.Do not transfer the S55375-C120 identity, firmware assumptions or project object schedule to another controller.

Specifications

Siemens identifies PXC5.E24.A S55375-C120 as a compact 24-point automation station with BACnet/IP and BACnet/SC, system-management functions and up to six TX-I/O modules.1

Exact hardware
PXC5.E24.A, order number S55375-C1201
Onboard and expansion I/O
24 onboard points: 2 DI, 8 UIO, 8 XIO and 6 relay outputs; up to 120 points with six TX-I/O modules1
Ethernet BACnet
BACnet/IP over UDP/IP and BACnet/SC over WSS and HTTPS with TLS 1.32
Field-level interfaces
Two EIA-485 ports configurable for Siemens P1, BACnet MS/TP or Modbus RTU2
BACnet profile evidence
Current PICS includes ReadProperty and ReadPropertyMultiple services and standard analog and binary input and value object types3
Evidence gap
No installed firmware, active transport, device instance, commissioned object export, client permission policy or verified Edge pairing13

Interface

Documented measurements and integration boundaries for PXC5.E24.A.

  • Potential temperatures, pressures, flows, equipment states and energy values can appear as project-defined BACnet input or value objects.
  • For each approved object retain device and object identifiers, object type, name, description, engineering unit, source, update behavior and reliability or status information.
  • A value integrated from Modbus RTU or BACnet MS/TP must retain its original field-device identity, scale, unit and communications status.
  • Commandable values, priority-array writes, schedules, alarm acknowledgements, PPCL logic, parameters and physical outputs remain outside this guide.

Assessment

PXC5.E24.A S55375-C120 after firmware, project, transport, PICS, object export and Edge client support are confirmed; no released path or control.

InteroperabilitySupported with conditions
Siemens publishes exact-model BACnet/IP, BACnet/SC and BACnet MS/TP support plus a current PICS with read-property services, while project object identities and Edge client support remain unproven.23
AccuracyNot yet assessed
The controller supports diverse local and integrated points, but source accuracy, scale, unit and update behavior belong to each commissioned object and field device.1
SecuritySupported with conditions
Siemens documents BACnet/SC with TLS 1.3 and protected engineering interfaces, but the installed certificates, trust, accounts and network policy remain project evidence.2
ReliabilityNot yet assessed
The PICS establishes services and object types, but no retained project evidence proves polling limits, update timing, reliability propagation or restart behavior for an external Edge client.3
RuggednessSupported with conditions
Siemens publishes the controller's supply, mounting and environmental specifications; the installation must follow the exact data-sheet orientation and enclosure requirements.1
ScalabilitySupported with conditions
The model supports up to 120 local and TX-I/O points and two field-level networks, but an external monitoring workload requires its own object and polling budget.12
LifecycleWell supported
Siemens publishes current exact-model data and a 2026 PICS revision with distinct order codes and engineering references.13

Setup

  1. Confirm the exact controller and project

    Record PXC5.E24.A S55375-C120, serial number, firmware, DT+ and ABT Site versions, project backup, device instance and current PICS. Do not substitute the no-WLAN or earlier PXC5.E24 hardware.

  2. Identify the active BACnet transport

    Confirm whether the commissioned system uses BACnet/IP, BACnet/SC or BACnet MS/TP. Treat each as a separate client path. Do not downgrade BACnet/SC or assume an Edge BACnet/SC client from controller capability.

  3. Export a read-only object schedule

    With the Desigo owner, retain only approved measurement and state objects with identifiers, types, units, source, update behavior, reliability and commandability. Exclude commandable and life-safety objects.

  4. Prove observations without changing control

    On an approved controls network, compare a small object set with the Desigo interface and original sensors or meters. Test stale data, restart and communications loss. Issue no WriteProperty request.

Common questions

Does BACnet/SC support on PXC5.E24.A prove an Edge connection?
No. Siemens proves BACnet/SC on the controller. A connection also requires a compatible Edge BACnet/SC client, certificate lifecycle, trust configuration and commissioned network. BACnet/SC must not be treated as BACnet/IP.23
Can an external client read every configured point?
Not from the datasheet alone. The commissioned application determines object identities and exposure, and the site security policy determines access. Use an authorised object export and a bounded read-only allowlist.13
Can this guide write setpoints or outputs?
No. The PICS includes write services, but this guide releases no WriteProperty operation, priority-array change, schedule edit, alarm acknowledgement, parameter change or physical output command.3

Sources

  1. Desigo Modular automation station PXC5.E24.A datasheet A6V14319960 (opens in a new tab) Siemens Smart Infrastructure
  2. PXC5.E24.A datasheet: Interfaces (opens in a new tab) Siemens Smart Infrastructure
  3. Desigo PXC.A BACnet PICS A6V13495554 (opens in a new tab) Siemens Smart Infrastructure

Further reading

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