SIEMENS 6ES7 317-2AK14-0AB0 High-performance CPU

6ES7: SIMATIC S7 automation series

3: S7-300 PLC platform

17: CPU317, high-performance CPU

2: Dual-interface version

A: DP interface variant (no Profinet port, differs from 2EK14 PN/DP model)

K: Hardware revision code

14: Firmware version V2.7

0AB0: Product packaging code, standard German original model

Full designation: CPU317-2DP, S7-300 Central Processing Unit, 1MB work memory, dual DP interfaces, MMC micro memory card mandatory

2. Key Technical Specifications
3. Memory

Work memory: 1MB (program + data)

Retentive memory: 256KB

Programs, project files and firmware are fully stored on MMC card. CPU cannot start without MMC card.

2. Execution Performance

Bit instruction: 25ns; Word instruction: 30ns; Fixed-point instruction: 40ns; Floating-point instruction: 160ns

3. Communication Interfaces (2 Independent DP Ports)

Port1: MPI / PROFIBUS-DP, max. 12Mbps, configurable as DP master/slave

Port2: Independent PROFIBUS-DP, master/slave, dual DP bus (this model has no Ethernet Profinet port)

4. I/O Capacity

Max. digital I/O: 65536 points (Process Image area: 8192 Bytes)

Max. analog channels: 4096 channels

Max. expansion racks: 3 racks (main rack + 3 expansion racks)

Supports FM function modules and CP communication modules

5. Electrical & Mechanical Data

Power supply: DC24V, power consumption approx. 3.5W

Dimensions: 40mm×125mm×130mm, weight approx. 0.406kg

Operating temperature: 0~60℃ (standard S7-300 range)

6. Programming Software: STEP7 V5.x, TIA Portal (Classic Mode)
7. Product Lifecycle

Officially entered phase-out stage (PM400) from 2023-10-01. New project orders are no longer accepted; spare parts remain available. Circulating units on market are mainly stock items or used/refurbished modules.

Comparison within series:

6ES7317-2AJ10-0AB0: 512KB work memory, older generation; 2AK14 is upgraded version with doubled memory and improved performance. Direct replacement with AJ10 is invalid if program size exceeds 512KB.

6ES7317-2EK14-0AB0: CPU317-2PN/DP with Profinet port, 1MB work memory. Hardware base compatible with AK14, but different communication interfaces, not directly interchangeable.

4. Typical Application Scenarios

Main controller for production lines, distributed I/O systems over multi-DP buses

Machine tools, metallurgy, paper, packaging, rubber & plastic and other medium-to-large automation equipment

Multi-drive DP bus control with dual DP network segmentation (one bus for field I/O, one bus for inverters)

PCS7 DCS slave stations, legacy production line retrofit projects

5. Model Selection & Replacement Solutions

5.1 Direct replacement on same platform (retrofit of legacy projects, minimal modification)

Same model: 6ES7317-2AK14-0AB0 (spare procurement. Attention required for MMC migration and firmware version matching)

⚠️Note: MMC card cannot be simply unplugged and inserted into new CPU; program and hardware configuration must be re-downloaded. Verify firmware version before replacement to avoid unexpected shutdown.

5.2 Cross-platform upgrade (Recommended for new projects)

S7-300 discontinued, recommended upgrade to S7-1500 series:

CPU1511C-1PN / CPU1513C-1PN; existing DP bus can be retained via ET200SP IM155-6DP interface module for legacy DP slaves.

5.3 Domestic alternative

Domestic PLC (Inovance, Xinje, Co-Trust etc.). Program and DP communication configuration must be completely rewritten. STEP7 project cannot be directly migrated. Suitable for full line renovation.

6. Installation & Maintenance Guidelines
7. Mandatory MMC requirement: Minimum 4MB, 8MB recommended. PLC fails to run if MMC is damaged or missing. All programs reside on MMC; no onboard storage in CPU.
8. Mounting: DIN rail mounting, S7-300 backplane bus. PS307 power supply module is mandatory.
9. Earthing: Single-end grounding for DP cable shield to reduce EMC interference. Terminating resistors configured separately for each DP bus.
10. Status LEDs: SF (system fault), BF (bus fault), RUN/STOP. For DP bus faults, check terminating resistors, wiring and DP address conflicts first.
11. Common Troubleshooting
12. SF ON, BF flashing: DP cable breakage, missing terminating resistor, slave station fault, DP address conflict.
13. No RUN after power-up, STOP LED steady ON: MMC missing/damaged, firmware corruption, program error.
14. Program download failure: Firmware mismatch in STEP7, wrong CPU order number selected in hardware configuration.
15. Parameter loss after power cycle: Incorrect retentive area setup, MMC card not fully saved.
16. Foreign Trade Information

HS Code: 85371011 (Programmable Logic Controller PLC)

Export Control: ECCN EAR99H, non-military item, normal industrial export.

9. Inspection Checklist for Second-hand Units
10. Visual check: No burn marks, no oxidation on backplane bus contacts, no water ingress or corrosion.
11. Power-on test: Insert functional MMC card; CPU enters RUN mode normally without SF/BF alarms.
12. Firmware reading: Read firmware V2.7 online via STEP7, cross-check with label order number.
13. Communication test: Test MPI/DP ports separately to verify both DP channels are functional.
14. Serial number verification: Read internal serial number to confirm non-relabeled refurbished module.

STEP7 Hardware Configuration Template｜6ES7317-2AK14-0AB0 (CPU317-2DP, V2.7)

Applicable software: STEP7 V5.4 / V5.5 / V5.7; TIA Portal Classic Mode can import this hardware configuration

Rack: UR rack (S7-300 rail, Rack 0)

1. Rack Slot Allocation (HW Config)

⚠️Important: This model has no Profinet Ethernet port, only two PROFIBUS-DP interfaces

2. Core CPU Properties (Double-click CPU to open properties)

2.1 General

Order number: 6ES7317-2AK14-0AB0

Firmware version: V2.7

Work memory: 1MB

Load memory: MMC dependent (8MB recommended, 6ES7953-8LG30)

2.2 Memory

Retentive Settings

Memory bits M: MB0~MB15 set as retentive by default

Timers, Counters: Retention can be ticked

DB blocks: Tick “Retentive” in DB properties, data saved to MMC after power loss

Process Image

Input PI: 8192 Bytes

Output PQ: 8192 Bytes

Partitioned process image available (OB1/OB35 partition refresh, suitable for high-speed DP bus)

2.3 Cycle / Clock

Cycle monitoring watchdog: Default 500ms, maximum 6000ms

Minimum cycle time: Default 0ms

Clock memory byte: MB10 recommended (bit0~bit7:10Hz,5Hz,2.5Hz,2Hz,1Hz,0.5Hz,0.2Hz,0.1Hz)

2.4 Interrupt OB Blocks

Cyclic interrupt OB35: Default 100ms, adjustable 1~60000ms (100/200ms commonly used for DP control)

Hardware interrupt OB40, Diagnostic interrupt OB82, Rack fault OB86, DP slave fault OB87 enabled on demand

2.5 Protection

Protection level: 1(no protection)/2(read protection)/3(read-write protection)

Password: Configurable on site, activated after hardware configuration download

Mode: Protection level editable under STOP mode

3. Dual DP Interface Configuration (Critical: Two independent DP subnets)

✅Port X1: MPI / PROFIBUS-DP (Port1)

1. Interface type: MPI or DP (mutually exclusive)
2. Bus parameters:

Baud rate: 187.5k / 500k / 1.5M / 12M (DP max.12Mbps)

Station address: 2 recommended (MPI default 2; DP master customizable 1~126)

Highest station address HSA:126

3. Mode: DP Master, can also be set as DP Slave

Purpose: MPI programming download / Subnet 1 for distributed I/O and drives

✅Port X2: Independent PROFIBUS-DP (Port2, DP-only, no MPI)

1. Create a new separate PROFIBUS subnet (physically isolated from X1)
2. Bus parameters: Baud rate matched to slaves on this subnet, max.12Mbps
3. DP station address: Must not overlap addresses in X1 subnet, e.g. 3
4. Mode: DP Master (most common), supports DPV0/DPV1

Purpose: Subnet 2 for inverters and DP instruments. Load separation on two buses to reduce bus interference.

General bus rule: Terminating resistor ON at both ends of bus, OFF at intermediate nodes; single-end shielding earthing.

4. Address Map Template (Default Range)

Input I: 0 ~ 8191 Byte

Output Q: 0 ~ 8191 Byte

Peripheral Input PI: 0 ~ 8191 Byte

Peripheral Output PQ: 0 ~ 8191 Byte

Memory bit M: 0~8191 Byte

Timer T: 0~2048

Counter C: 0~2048

Local data L: Max.32768Byte per priority class, max.2048Byte per FB block

5. Recommended OB Block Template for New Projects

OB1: Main cycle

OB10: Time-of-day interrupt (as required)

OB35: Cyclic interrupt (100ms)

OB82: Diagnostic interrupt (module fault alarm)

OB86: Rack/DP slave loss interrupt (mandatory for DP projects)

OB87: DP communication fault interrupt

OB121: Program error; OB122: Peripheral access error (retained to prevent CPU stop)

6. Download & MMC Precautions
7. MMC card must be inserted before downloading hardware configuration; download impossible without MMC.
8. Firmware compatibility: Hardware library in STEP7 must contain CPU317-2DP V2.7; older hardware library cannot locate this CPU.
9. CPU hardware replacement: Hardware configuration + user program must be re-downloaded. MMC cannot be transplanted directly.
10. Dual DP master: Slaves configured separately on each DP subnet; cross-subnet direct addressing unavailable.
11. Common Configuration Errors
12. Wrong model selection: Accidentally select 6ES7317-2EK14 (PN port version), causes compile error in hardware.
13. Two DP ports assigned to same subnet: Bus conflict, BF LED flashing.
14. Watchdog time set too short: DP bus failure triggers OB80 timeout and CPU stop.
15. Insufficient process image size: I/Q address overflow with large-scale distributed I/O.
16. Export Template Operation Guide
17. Complete above settings in HW Config
18. Menu: Station → Save and Compile
19. Export as .cfg or export station in SIMATIC Manager for project archiving
20. Backup: Export hardware configuration separately for reuse on similar production lines