Application Scenarios
A regional plastics injection molding plant in Northern Italy had been running its S5-135U controller with an original 6ES5374-2KG21 memory card since 1994. When the plant’s engineering team recently attempted to modify the molding cycle parameters, they discovered that the original Flash-EPROM had reached the end of its reliable write-cycle life—program changes could no longer be committed, and the CPU began reporting memory inconsistencies during warm restarts.
Faced with the choice of a full S7-1500 migration (estimated at €180,000 and 4 weeks of production loss) versus sourcing a tested replacement 6ES5374-2KG21, the team chose the latter. A refurbished, fully tested unit was procured from a specialized S5 spare parts provider, the original program was transferred via PG programmer, and the card was installed during a planned weekend shutdown. The 6ES5374-2KG21 restored full programmability to the controller, allowing the plant to implement the new molding parameters immediately. For legacy S5 operators, the 6ES5374-2KG21 is not merely a memory card—it is the key to unlocking continued productivity from decades-old automation investments without disrupting proven control logic.
Parameter
| Main Parameter | Value / Description |
|---|---|
| Product Model | 6ES5374-2KG21 |
| Manufacturer | Siemens AG |
| Product Category | SIMATIC S5 Long-Type Memory Card (Flash-EPROM) |
| Memory Technology | 5V-only Flash-EPROM (non-volatile) |
| Storage Capacity | 128 KB |
| Form Factor | Long type (Lange Bauform) |
| Compatible Systems | SIMATIC S5 controllers and communication processors |
| Interface | Standard S5 memory card edge connector |
| Operating Voltage | 5 V DC (supplied by CPU/motherboard) |
| Data Retention | Non-volatile — no backup battery required |
| Physical Dimensions | Length approx. 121 mm; Width approx. 7.5 mm; Height approx. 3.5 mm |
| Weight | 0.047 kg |
| Commodity Code | 85389091 |
| Operating Temperature | 0 °C to +60 °C (standard S5 cabinet environment) |
| Mounting | Direct insertion into dedicated memory card slot |
| Country of Origin | Germany |
| Lifecycle Status | Discontinued by Siemens — available as refurbished/tested spare |
| Typical Availability | Refurbished, repaired, or exchange units with 12–24 month warranty |
