Sale and repair of SIEMENS SIMATIC S7-300 parts

PLC system for machines, production lines and automation systems

SIEMENS SIMATIC S7-300 is a modular PLC system used to control standalone machines, production lines, conveyors and medium-sized automation systems. Depending on the application, the system can be assembled from a CPU, digital and analog signal modules, communication processors, function modules, power supplies and accessories.

S7-300 modules are also used in ET 200M distributed I/O stations connected through PROFIBUS or PROFINET. When replacing a part, we therefore verify not only the order number but also the system configuration, interface-module type and project version.

CPU 312, 313, 314, 315, 317 and 319

In the SIMATIC S7-300 CPU category, we offer CPU 312, CPU 313, CPU 314, CPU 315, CPU 317 and CPU 319 processors. The individual types differ in performance, work-memory capacity, communication features and expansion options.

We supply standard CPUs, compact CPU 31xC versions with integrated inputs and outputs, processors with PROFIBUS DP or PROFINET interfaces, fail-safe CPU 31xF models and SIPLUS versions for demanding operating environments.

When looking for a replacement, comparing only the CPU designation is not sufficient. The complete order number, hardware and firmware version, work-memory capacity, MMC card type, communication interfaces and device support in the specific STEP 7 version must all be verified.

Digital input and output modules

For connecting pushbuttons, limit switches, sensors and other binary signals, we supply digital input modules.

For controlling contactors, valves, relays and signalling devices, we offer digital output modules and combined digital input and output modules.

When selecting a module, we check the number of channels, voltage level, current load, transistor or relay outputs, electrical isolation, diagnostic functions and compatibility with the front connector.

Analog input and output modules

For measuring and controlling technological variables, we supply analog input modules, analog output modules and combined analog input and output modules.

We offer modules for voltage and current signals, RTD resistance sensors, TC thermocouples, HART communication and the measurement of temperature, pressure, flow, level, position and other process variables.

For analog modules, we also verify the signal range, resolution, number of sensor wires, electrical isolation and the parametrization method used in the hardware configuration.

CP communication processors and IM interface modules

SIMATIC S7-300 communication modules connect the PLC to other control systems, operator panels, drives, supervisory applications and industrial networks.

We supply, for example, CP 341, CP 342 and CP 343 processors for serial communication, PROFIBUS, Industrial Ethernet and PROFINET. Our range also includes IM interface modules for local system expansion and distributed ET 200M stations.

FM function modules

SIMATIC S7-300 function modules are designed for specialized technological tasks such as high-speed counting, frequency measurement, positioning, axis control, closed-loop control or processing specific signals.

When replacing an FM module, we verify the order number, parametrization, technology blocks used, links to the PLC program and any connected sensors, encoders or drives.

Power supplies, MMC cards and accessories

To power the system, we offer power supplies for SIMATIC S7-300 in different performance versions. When replacing a power supply, we check the input voltage, output current, module width and available space on the mounting rail.

We also supply front connectors, mounting rails, interconnection components, bus connectors, backup batteries, MMC memory cards and other SIMATIC S7-300 accessories.

The MMC card is an important part of most S7-300 CPUs. When replacing a CPU, we therefore recommend verifying its capacity, condition, program content and compatibility with the replacement processor.

STEP 7 software and SIMATIC Manager

For programming, configuration and diagnostics, we offer software and licences for SIMATIC S7-300, including STEP 7 and versions supporting older projects in SIMATIC Manager.

When replacing a CPU or communication module, we can help verify whether the specific hardware and firmware version is supported by the software used and whether the original project can be transferred to the replacement device.

SIMATIC S7-300 part repairs

We professionally repair, diagnose and functionally test CPUs, I/O modules, communication processors, function modules and power supplies.

Depending on the equipment type, we check power circuits, communication, memory, digital and analog channels, connectors and module behaviour under operating load. If a repair is not possible or economically viable, we check the availability of an identical replacement part.

Compatible replacements for discontinued modules

For selected digital and analog I/O modules, power supplies and accessories, we also offer compatible replacements for SIMATIC S7-300 parts. These can extend the service life of a machine without immediately replacing the entire control system.

Before using a replacement, we verify the electrical parameters, number of channels, front-connector wiring, supported functions, diagnostic options and any required changes to the hardware configuration.

S7-300 lifecycle and migration to S7-1500

The SIMATIC S7-300 and ET 200M product families are gradually moving into later stages of their product lifecycle. The availability of individual order numbers may therefore differ, and repairs, stocked spare parts and verified program backups are becoming increasingly important for equipment expected to remain in operation.

For critical technology, we recommend identifying the important CPUs, power supplies, communication processors and I/O modules and deciding which components should be kept as on-site emergency spares.

As part of a planned modernization, the S7-300 can be replaced in many applications with the newer SIMATIC S7-1500 platform. However, this is not a direct one-for-one replacement of individual modules. The PLC program, communication, distributed I/O, drives, HMI, technology functions and any safety-related parts of the application must all be assessed.

Why buy SIMATIC S7-300 parts from FOXON?

• new original parts supplied directly by Siemens
• refurbished and discontinued parts from verified European partners
• access to more than 900,000 spare parts in European warehouses
• our own spare-parts warehouse in Liberec
• verification of the order number, hardware, firmware and system compatibility
• professional repairs, diagnostics and functional testing
• support with replacing CPUs, I/O, CP, FM and IM modules, power supplies and MMC cards
• compatible replacements for selected discontinued modules
• support with program transfer and migration to SIMATIC S7-1500
• express delivery available for selected components
• 3 to 24-month warranty on supplied parts and repairs
• SIEMENS SIMATIC S7 PLC programming training

How do you correctly identify the required S7-300 part?

Send us the complete SIEMENS order number, including all characters after the hyphen. We recommend attaching a photograph of the product nameplate showing the equipment type and its hardware and firmware versions.

For CPUs and communication processors, it is also helpful to include the STEP 7 version, communication interfaces used, MMC card type and information about the other modules in the system.

Can a newer S7-300 CPU be used as a direct replacement?

Sometimes, but the hardware and firmware compatibility, memory capacity, MMC card, communication interfaces and support for the replacement CPU in the specific STEP 7 project version must always be checked first. The CPU 315 or CPU 317 designation alone is not sufficient to determine a safe replacement.

Do you also supply discontinued S7-300 parts?

Yes. We source discontinued and obsolete components through a network of verified European warehouses. Depending on availability, we can offer a new original, refurbished or used part, repair the original equipment, supply a compatible replacement or propose a modernization.

Can you transfer the program to a replacement CPU?

Yes, provided that a working project backup, the original MMC card or a readable program in the CPU is available. Before replacement, we verify the processor type, firmware, hardware configuration and compatibility of the program with the replacement device.