Siemens 6ES7951-0KG00-0AA0 SIMATICS 7 Memory Card

Brand

Siemens

Product Type

SIMATIC S7 Memory Card (Flash-EPROM)

Compatible Systems

SIMATIC S7-300 CPUs with memory card slot

Memory Capacity

128 KB

Memory Type

5 V Flash-EPROM, 8-bit data width

Functions

Program storage, data backup, firmware updates

Operating Voltage

5 V DC (supplied via PLC backplane)

Operating Temperature

0 °C to +60 °C

Storage Temperature

–40 °C to +85 °C

Relative Humidity

5–95% , non-condensing

Data Retention

≥ 10 years (typical, without power)

Write/Erase Cycles

≥ 100,000

Shock Resistance

Up to 50 g

Vibration Resistance

5–150 Hz

Form Factor

CompactFlash (CF), short version

Dimensions

Approx. 43 × 36 × 3 mm

Weight

Approx. 38g

Q: What are the different types of SIMATIC memory cards and how do they differ?

A: Siemens offers several types of memory cards across its SIMATIC PLC families, each with distinct characteristics. For the S7-300 series, the primary memory card is the Flash-EPROM (FEPROM) card (such as the 6ES7951-0KG00-0AA0), which uses non-volatile memory technology to retain user programs and data even during power loss without requiring a backup battery . In contrast, the S7-400 series offers both RAM cards (which require a battery to maintain data during power outages) and FEPROM cards (battery-independent storage) . For newer platforms like the S7-1200 and S7-1500, Siemens exclusively uses SIMATIC Memory Cards (SMC) based on SD/Flash technology, which are not interchangeable with commercial SD cards as standard Windows formatting will render them unusable .

Q: Can the SIMATIC memory card be used to expand the CPU's work memory or load memory?

A: No, the SIMATIC memory card does not expand the CPU's internal work memory (RAM) or total load memory capacity. For S7-300 CPUs using an FEPROM card (like the 6ES7951 series), the card serves as a separate, independent load memory that stores the user program and system configuration . When the CPU starts up, it automatically copies the program from the FEPROM card into its internal work memory for execution . However, the card does not increase the total available work memory. For S7-1200 CPUs, the SIMATIC Memory Card can operate in "Program" mode, where all project data is stored on the card instead of the internal load memory, but again, the total load memory remains unchanged .

Q: Is the SIMATIC memory card mandatory for all Siemens PLCs?

A: No, the SIMATIC memory card is not mandatory for all Siemens PLC families. For S7-1200 CPUs, the memory card is optional and not required for basic operation; programs can be stored directly in the CPU's internal Flash memory . However, the memory card provides additional functionality, including program transfer, firmware updates, password recovery, and data logging . For S7-1500 CPUs, the SIMATIC Memory Card is mandatory because the CPU has no internal load memory; the card must always be inserted for the CPU to operate . For S7-300 CPUs, the memory card is required only when using CPUs without integrated load memory .