Siemens 6ES7312-5BE03-0AB0 Compact CPU Module

Siemens 6ES7312-5BE03-0AB0 SIMATIC S7-300 CPU 312C Compact CPU

Product Introduction

The Siemens 6ES7312-5BE03-0AB0 is a compact CPU from the SIMATIC S7-300 family. This CPU 312C unit combines logic processing with onboard I/O. It includes 10 digital inputs and 6 digital outputs on the same module. Furthermore, it offers 2 fast counters with a 10 kHz rating. Many engineers choose this Siemens compact controller for space-saving applications. The firmware version is V2.6, and it works with STEP 7 V5.3 SP2 or higher after a hardware update.

Technical Specifications

• Rated voltage (DC): 24 V (range 20.4V to 28.8V)

• Typical power loss: 6 W

• Current consumption (rated): 500 mA

• Inrush current (typ.): 11 A, I²t 0.7 A²·s

• Firmware version: V2.6

• Hardware product version: 01

• Work memory: 32 kbyte (non-expandable)

• Load memory: MMC plug-in, max. 4 Mbyte

• Data retention on MMC: min. 10 years

• Programming package: STEP 7 V5.3 SP2 or higher with HW update

Additionally, this CPU processes bit operations in just 0.2 µs typically. For fixed-point arithmetic, it takes 5 µs, while floating-point operations need 6 µs. Meanwhile, the module supports up to 1,024 blocks in total (DBs, FCs, FBs).

Integrated Digital I/O Details

Digital Inputs (10 channels)

• Input voltage for signal "1": +15V to +30V

• Input voltage for signal "0": -3V to +5V

• Input current for signal "1": typ. 9 mA

• Input delay parameterizable: 0.1 / 0.3 / 3 / 15 ms

• Cable length (shielded): max. 1,000 m

Digital Outputs (6 channels)

• Output voltage for signal "1": min. L+ (-0.8V)

• Output current rated value: 500 mA

• Short-circuit protection: Yes (clocked electronic, typ. 1A threshold)

• Switching frequency (resistive load): max. 100 Hz

• Pulse output frequency: max. 2.5 kHz

• Total current per group (horizontal, up to 40°C): max. 2 A

Specifically, the 6ES7312-5BE03-0AB0 includes 2 high-speed outputs. It also has 2 fast counters (10 kHz) for simple positioning tasks.

Memory and Data Areas

• S7 counters: 128 (adjustable retentive, range 0-999)

• S7 timers: 128 (range 10 ms to 9,990 s)

• IEC counters/timers: Unlimited (SFB type, RAM-limited)

• Flag memory: 128 bytes (retentive MB0 to MB127)

• Data blocks: max. 511 (each up to 16 kbyte)

• Local data per priority class: 256 bytes

• I/O address area: 1 kbyte each for inputs and outputs

• Process image: 128 bytes each for inputs and outputs

Moreover, the CPU retains all data without a battery. The MMC guarantees maintenance-free backup for programs and data.

Interfaces and Communication

• MPI interface: 1 x RS485 (max. cable length 50 m without repeater)

• Industrial Ethernet: None

• RS422: None

• DP masters: None integrated (up to 4 via CP modules)

• Clock synchronization: Supported via MPI (master or slave)

Therefore, the Siemens 6ES7312-5BE03-0AB0 connects well to programming devices and HMIs through the MPI port.

Mechanical & Environmental Parameters

• Dimensions (W x H x D): 80 mm x 125 mm x 130 mm

• Weight: approx. 409 g

• Protection class: IP20

• Ambient temperature (horizontal, up to 40°C): full I/O capacity

• Ambient temperature (horizontal, up to 60°C): reduced load (5 DI max, 1.5A DO)

Furthermore, the CPU supports horizontal or vertical installation. For vertical mounting at 40°C, the maximum I/O reduces to 5 digital inputs and 1.5A output current.

Installation Guidelines

First, always disconnect the power supply before handling the CPU 312C. Next, snap the Siemens 6ES7312-5BE03-0AB0 onto a 35mm DIN rail. Then, insert a micro memory card (MMC) into the slot. The CPU will not operate without an MMC. After that, connect the 40-pin front connector for I/O wiring. Additionally, use a type C miniature circuit breaker (min. 2A) or type B (min. 4A) for power line protection. Finally, download your STEP 7 program via the MPI interface.

For a spare part replacement, remove the old CPU first. Insert the 6ES7312-5BE03-0AB0 and insert the existing MMC. Power on the system and verify the firmware version V2.6.

Expansion Limitations

Please note the following restrictions:

• Maximum expansion units: 0 (no rack expansion)

• Maximum modules per rack: 8

• Maximum racks: 1

• Operable FMs: up to 8 (recommended)

• Operable CPs (PtP): up to 8

• Operable CPs (LAN): up to 4

Therefore, this compact CPU works best for standalone small machines or distributed I/O via CP modules.

Packaging List

• 1 x Siemens 6ES7312-5BE03-0AB0 CPU 312C module

• 1 x 40-pin front connector (screw-type)

• 1 x Labeling strip

• 1 x Bus connector cover

Note: Micro memory card (MMC) is not included and must be purchased separately. No certificate or warranty document is included in the package.

Shipping Methods

We ship exclusively via FedEx, UPS, or DHL. Tracking numbers will be provided within 24 hours after dispatch.

Frequently Asked Questions (FAQ)

1. Does the Siemens 6ES7312-5BE03-0AB0 work without a micro memory card?
No, this CPU 312C requires an MMC for operation. The work memory itself is non-expandable, but the MMC stores the load memory and retentive data. Without an MMC, the CPU will not start.

2. Can I use this spare part to replace an older CPU 312C with lower firmware?
Yes, the 6ES7312-5BE03-0AB0 with firmware V2.6 is backward compatible. However, you may need to upgrade your STEP 7 software to V5.3 SP2 or higher and perform a hardware update.

3. What is the maximum switching frequency for the high-speed outputs?
The high-speed pulse outputs handle up to 2.5 kHz with a resistive load. For standard outputs, the maximum switching frequency is 100 Hz with resistive load.

4. How many expansion racks can I connect to this CPU?
None. This compact CPU supports only one rack with up to 8 modules. It has no integrated DP master, so you cannot add expansion racks directly. Use CP modules for distributed I/O.

5. Does the CPU retain data during a power outage?
Yes, the Siemens 6ES7312-5BE03-0AB0 uses the MMC for maintenance-free backup. The MMC retains program and data for at least 10 years without a battery. No battery is needed.