The Siemens 6ES7315-2AG10-0AB0 is the SIMATIC S7-300 CPU 315-2 DP — a central processing unit with an integrated 24 V DC power supply, 128 KB work memory, an MPI interface and a second PROFIBUS DP master/slave interface. As an independent third-party supplier of obsolete and hard-to-find automation parts, BXLY PLC supplies the 6ES7315-2AG10-0AB0 and its direct successor for plants that cannot yet migrate off the S7-300 platform. This guide covers its specifications, compatible replacements, common failure points and how to request a quote.
Quick Specifications
| Attribute | Detail |
|---|---|
| Manufacturer | Siemens |
| Series | SIMATIC S7-300 |
| Type | CPU 315-2 DP — central processing unit |
| Article number (MLFB) | 6ES7315-2AG10-0AB0 |
| Work memory | 128 KB |
| Power supply | Integrated 24 V DC supply |
| Interface 1 | MPI (multi-point interface) |
| Interface 2 | PROFIBUS DP — master and slave |
| Load memory | Micro Memory Card (MMC) required — program is stored on the MMC, not battery-backed RAM *(exact MMC size/MLFB — 需核实)* |
| Engineering software | STEP 7 (SIMATIC Manager / STEP 7 V5.x) |
| Status | Discontinued — no longer sold as a new catalogue part |
| Direct successor | 6ES7315-2AH14-0AB0 (CPU 315-2 DP, 256 KB) |
| Platform phase-out | S7-300 / ET 200M: PM400 announcement 2023-10-01; PM410 type discontinuation 2025-10-01 (267 modules affected) |
What the 6ES7315-2AG10-0AB0 Does
The 6ES7315-2AG10-0AB0 is the "brain" of a SIMATIC S7-300 station. It executes the user program, manages the process image and drives central and distributed I/O. Unlike the S7-1500, the S7-300 stores the user program on a Micro Memory Card (MMC) rather than in battery-buffered RAM — so the MMC is effectively the program: remove it and the CPU cannot run the project.
Its two communication interfaces are why it was one of Siemens' most widely installed mid-range CPUs. Interface 1 provides MPI for programming, HMI and small peer-to-peer networks, while interface 2 is a native PROFIBUS DP master/slave port — it can both control remote I/O and intelligent DP slaves and act as a DP slave to a higher-level controller. That DP port made the 315-2 DP a staple of distributed, networked machines and small process plants.
Because it uses the open S7-300 I/O family (SM 321/322/331/332/334 signal modules plus CP communication processors), the 2AG10 typically drives a full S7-300 rack plus DP-expanded remote I/O. With the S7-300 platform now past its type-discontinuation milestone (2025-10-01), the practical decision for existing users is whether to replace the CPU in-kind or re-engineer onto S7-1500.
Compatible & Alternative Modules
| Alternative | Family | Work memory | Key difference vs. 2AG10 |
|---|---|---|---|
| 6ES7315-2AH14-0AB0 CPU 315-2 DP | S7-300 CPU 315-2 DP | 256 KB | Siemens-designated direct successor. Same MPI + PROFIBUS DP layout; double the work memory. |
| 6ES7315-2AF03-0AB0 | S7-300 CPU 315-2 DP | 64 KB | Earlier 315-2 DP generation; half the memory of the 2AG10. |
| 6ES7315-2EG10-0AB0 | S7-300 CPU 315-2 PN/DP | 128 KB | Replaces the DP port with PROFINET (built-in Ethernet) while keeping MPI/DP. |
| 6ES7315-2EH14-0AB0 | S7-300 CPU 315-2 PN/DP | 384 KB | Higher-memory PN/DP variant; three times the 2AG10 work memory. |
| 6ES7331-7KF02-0AB0 SM331 analog input | S7-300 SM 331 | n/a | Same-platform analog input module commonly used alongside the 315-2 DP. |
Compatibility notes
- All the CPUs above occupy a single CPU slot on the S7-300 rail and use the same S7-300 signal modules (SM 321/322/331/332/334) and CP 34x communication processors.
- The 2AG10 needs a Micro Memory Card to hold the program; source it separately if you are replacing only the CPU. *(Confirm the exact MMC size/MLFB against your project's memory requirements — 需核实.)*
- Swapping to the 2AH14 successor normally keeps existing I/O and wiring, but the STEP 7 hardware configuration must be updated to the new order number and the program recompiled. Firmware/version differences should be checked before commissioning.
- Long-term migration beyond S7-300 means moving to the S7-1500 platform, which requires re-engineering the rack and re-testing the application — S7-300 signal modules do not move across directly.
Common Failure Points & Replacement Signs
- Micro Memory Card fault. If the MMC is missing, undersized or corrupted, the CPU stays in STOP with the SF (system fault) LED lit and no program loaded. Because the program lives on the MMC, a failed card can take a station down completely — budget a spare MMC alongside the CPU.
- PROFIBUS DP communication faults (BF LED). A blinking or steady BF indicator usually points to a DP slave, termination or cabling issue — but on high-hour units the DP interface on the CPU itself can degrade and refuse to reconnect after a power cycle.
- Repeated STOP / SF faults after a swap. Fitting a different CPU version (e.g. 2AH14 or a different firmware) without updating the STEP 7 hardware configuration commonly produces configuration mismatches and a CPU that will not enter RUN.
- Power-section and capacitor ageing. These CPUs are now 15–20+ years old. Failing electrolytic capacitors and a weak 24 V supply section show up as spontaneous resets, random STOPs, or a CPU that will not power up — a classic "replace or repair" call.
- Clock / time-stamp loss. The integrated real-time clock can lose time across power cycles once its backup is exhausted, corrupting time-stamped alarms and historical logs. *(Clock backup method is version-dependent — verify against the Siemens manual for your exact CPU. 需核实.)*
Availability & Lead Time
BXLY PLC supplies the 6ES7315-2AG10-0AB0 CPU 315-2 DP and the S7-300 family as an independent third-party supplier, across several condition grades — new old stock / factory surplus, refurbished and tested pulls, and used / as-removed units with an honest condition report. We do not publish prices on this page; availability, condition and lead time are confirmed per enquiry.
Request a Quote → with your required condition (new / refurbished / used), quantity and destination, and we will confirm live stock and lead time. A warranty applies to tested stock (terms confirmed on your quotation). Given the S7-300 phase-out, we recommend pairing a spare CPU with a correctly sized Micro Memory Card so a replacement can be commissioned without delay.
FAQ
Is the 6ES7315-2AG10-0AB0 discontinued?
Yes. It is no longer sold as a new catalogue part. The SIMATIC S7-300 / ET 200M system reached the PM400 phase-out milestone on 2023-10-01 and the PM410 type-discontinuation milestone on 2025-10-01; since then the components are offered as spare parts only.
What is the direct replacement for the 6ES7315-2AG10-0AB0?
Siemens designates the 6ES7315-2AH14-0AB0 (CPU 315-2 DP, 256 KB) as the direct successor. It keeps the same MPI + PROFIBUS DP interface layout and doubles the work memory. For a platform migration, the strategic successor is the S7-1500 family.
Can I replace the 2AG10 with the 2AH14 without rewriting my program?
In most cases yes, but the STEP 7 hardware configuration must be updated to the new order number and the program recompiled. Check firmware/version compatibility before commissioning, and verify any DP configuration against the existing network.
Does the 6ES7315-2AG10-0AB0 need a Micro Memory Card?
Yes. The user program is stored on a Micro Memory Card, not in battery-backed RAM. A correctly sized MMC must be fitted for the CPU to run your project.
How do I buy a 6ES7315-2AG10-0AB0 from BXLY PLC, and what does it cost?
BXLY PLC is an independent third-party supplier. Prices are not published; send your required condition, quantity and destination via the Request a Quote form and we will confirm availability, price and lead time.
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- 6ES7315-2AG10-0AB0 CPU 315-2 DP
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*BXLY PLC is an independent third-party supplier of obsolete and hard-to-find automation components and is not affiliated with, authorized by, or an authorized distributor of Siemens AG. All trademarks are the property of their respective owners. Specifications are compiled from manufacturer documentation and are provided for identification purposes; always confirm the exact revision against your project.*