SIEMENS 6ES7318-3EL01-0AB0

What is 6ES7318-3EL01-0AB0 and where is it used?

The SIEMENS 6ES7318-3EL01-0AB0 is the SIMATIC S7-300 CPU 319-3 PN/DP, a high-performance central processing assembly for modular automation solutions in existing installations. It is used wherever machines, production lines, or process systems require a high-performance CPU, traditional fieldbus connectivity, and Ethernet communication simultaneously. Typical applications include systems using PROFIBUS DP, MPI/DP, and PROFINET, such as packaging machines, assembly systems, conveyor technology, and retrofit projects. For maintenance personnel, the assembly is particularly relevant when an existing S7-300 CPU must be identified precisely, replaced quickly, or repaired economically after a failure. For purchasing departments, the exact article number is important because it directly determines the version, memory size, and communication interfaces.

Overview of the key technical data and what they mean

The CPU provides 2 MB of work memory, operates on 24 V DC, requires a SIMATIC Micro Memory Card (MMC), and offers three communication paths: 1 × MPI/DP with up to 12 Mbit/s, 1 × PROFIBUS DP master/slave interface, and 1 × PROFINET Ethernet interface with an integrated 2-port switch. In practice, this means that the assembly is suitable for both traditional S7-300 architectures with distributed I/O and Ethernet-based connections for HMI, PG/OP, and I/O devices. Siemens also specifies support for isochronous operation, an integrated web server, up to 124 DP devices as a DP master, and a total of 32 communication connections. Configuration and programming are carried out using STEP 7 V5.5 or later, with support for LAD, FBD, STL, SCL, CFC, GRAPH, and HiGraph.

Product status, life cycle status and obsolescence

For operators of legacy systems, the status of this CPU is particularly important. Siemens lists the 6ES7318-3EL01-0AB0 as a spare part, while the Siemens Portal also identifies the lifecycle status as “Prod. Cancellation”. This indicates an assembly that remains technically relevant but is already in an advanced stage of obsolescence, with increasing procurement and availability risks. For production and purchasing departments, this means that spare parts stockholding, repair capability, and qualified sourcing channels are becoming increasingly important. The Siemens migration documentation primarily focuses on modernisation paths: in the Siemens migration guide, the CPU 319-3 PN/DP is mapped to the S7-1500 CPU 1517-3 PN/DP. However, this represents a migration strategy rather than a simple 1:1 replacement within an existing S7-300 rack.

Available EICHLER services and when they are relevant in practice

For operators of ageing S7-300 systems, EICHLER services are particularly valuable when the cost of downtime exceeds the cost of repair or replacement. For 6ES7318-3EL01-0AB0, EICHLER offers Repair, Exchange, Used, and New options. The repair service is specified with a turnaround time of 2–5 days and includes technical cleaning, preventive maintenance, comprehensive functional testing, and a minimum 24-month warranty. Exchange, used, and new units are currently listed with delivery times of 1–3 days. In addition, a test report for CPU/central processing assemblies can be selected. For maintenance and purchasing departments, this provides practical flexibility: depending on the fault situation, it is possible either to retain the original assembly, minimise downtime, or secure spare parts availability for a discontinued platform in a more predictable manner.

Is 6ES7318-3EL01-0AB0 still an active Siemens product?

Siemens classifies the assembly as a spare part, and the Siemens Portal additionally lists the lifecycle status as “Prod. Cancellation”. For operators, this means that the CPU remains relevant for legacy systems, but it is no longer part of Siemens' active growth platform. As a result, the importance of forward-looking spare parts procurement, repair capability, and a robust service strategy increases significantly.

Does the CPU 319-3 PN/DP require a Micro Memory Card?

Yes. Siemens explicitly states in both the datasheet and the CPU documentation that the assembly requires a SIMATIC Micro Memory Card (MMC). The reason is that the CPU does not provide an integrated load memory for operation. In practice, this means that without a suitable MMC, neither reliable operation nor secure program transfer can be ensured. When replacing the CPU, the memory card should therefore always be treated as a critical commissioning component.

What are MPI/DP, DP, and PROFINET used for in everyday applications?

The three interfaces serve different purposes. MPI/DP remains important in many legacy systems for PG/OP service access and traditional communication. The second DP interface enables operation as either a DP master or DP slave for distributed I/O and older fieldbus structures. PROFINET, with its integrated 2-port switch, simplifies Ethernet connectivity for HMIs, engineering stations, and I/O devices without immediately requiring additional network hardware in every topology. For retrofit projects and spare parts management, this exact combination of interfaces is often the reason why the specific CPU variant must be sourced.

Which software is used to configure 6ES7318-3EL01-0AB0?

The Siemens datasheet specifies STEP 7 V5.5 or later for this CPU. Siemens also states that firmware updates require compatible STEP 7 versions. For operators of legacy systems, this is important because procuring the hardware alone is not sufficient. It is equally important to ensure that the existing engineering environment, project archive, and service workflows remain compatible with the platform. Particularly in older S7-300 installations, project versions, firmware revisions, and the PG/PC environment should be checked before procurement.

Is there a successor to the CPU 319-3 PN/DP?

For modernisation projects, Siemens identifies the CPU 1517-3 PN/DP within the S7-1500 platform as the target system in its migration guide. This is particularly relevant for operators who are planning a long-term platform upgrade rather than simply replacing a failed CPU. However, it is important to understand that this designation describes a migration path, not a simple mechanical or project-level replacement within an existing S7-300 configuration. Operators seeking to minimise downtime in the short term will generally still require the original CPU class or a specialised repair or exchange service.

When is repair more economical than exchange or purchasing a replacement unit?

Repair is generally the most economical option when the existing hardware and software platform are intended to remain unchanged and a planned reinstallation is more cost-effective than an immediate migration. On the EICHLER product page, repair is specified with a turnaround time of 2–5 days and includes technical cleaning, preventive maintenance, functional testing, and a minimum 24-month warranty. Exchange, used, and new units, on the other hand, are particularly attractive when downtime must be reduced to an absolute minimum; these services are currently specified with turnaround times of 1–3 days. For purchasing and production departments, this creates a clear decision framework balancing cost, speed, and operational risk.

Why is a test report useful for a CPU/central processing assembly?

On the EICHLER website, an optional test report for CPU/central processing assemblies can be selected for exchange and used-unit services. This is particularly useful for companies operating in critical production environments, where documentation is required internally or where a traceable verification of testing is needed before installation. It helps reduce queries between maintenance, purchasing, and quality departments, while also supporting a smooth handover to stores, spare parts management, and recommissioning processes.