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This central unit executes control programs for SIMATIC S5 automation systems. It processes both bit and word logic instructions efficiently. You can mount this unit directly into standard S5 racks.
Technical Specifications
| Parameter | Details |
|---|---|
| Brand | Siemens |
| Model | Siemens 6ES5188-3UA31 |
| Category | Central Unit (SIMATIC S5 Series) |
| Dimensions (H x W x D) | 250 mm x 85 mm x 210 mm |
| Weight | 1.52 kg |
| Processor Type | 16-bit microprocessor |
| Program Memory | 8 KB RAM (battery-backed) |
| Load Memory | 8 KB EPROM or EEPROM |
| Data Memory | 2 KB internal flags and timers |
| Processing Speed | 2.5 ms per 1K of bit logic |
| Number of Internal Components | 1 CPU + 2 memory modules + 1 power regulation circuit |
| Interface Type | Backplane bus + 1x TTY programming port |
| Built-in I/O | None (requires external S5 cards) |
| Power Supply | 115 V AC or 230 V AC (selectable) |
| Power Consumption | 18 VA typical |
| Built-in Energy Storage | 3300 µF capacitor + lithium battery socket |
| Battery Type | 3.6 V lithium (not included) |
| Data Retention (with battery) | Approximately 60 days |
| Status Indicators | 4 LEDs (RUN, STOP, BATT, BUS) |
| Operating Temperature | 0°C to 60°C |
Detailed Feature Overview
This central unit features a 16-bit processor for faster program execution. It completes 1K of bit logic in only 2.5 milliseconds. You can store up to 8 KB of user code in RAM or EPROM.
A 3300 µF capacitor provides short-term energy buffering during power disturbances. With an optional lithium battery, data retention extends to 60 days. Consequently, your control logic remains intact through brief outages.
You will find a TTY programming port on the front panel. This port connects to a programmer or PC using a suitable adapter. The backplane bus links directly to all S5 I/O modules automatically.
Installation and Programming
Siemens 6ES5188-3UA31 occupies the first slot of an S5 rack. Use STEP 5 software to write and upload your control programs. Set the voltage selector correctly before connecting AC power.