PANASONIC SF-C21 — Safety Relays
Panasonic SF-C21: safety control unit, Category 4, PL e, SILCL 3, 8 safety inputs, 2×2 PNP outputs, 8 preset logics, 10 ms.
Status: In production
Brand: Panasonic
Product: Safety control unit (8 preset logics, PL e)
Safety level: Category 4, PL e, SIL 3, SILCL 3
Safety inputs: 2 × 4 (IN1–IN8)
Control outputs: PNP, 2 outputs × 2, max. 300 mA per output
Response time (ON→OFF): 10 ms or less
Size: height 97 mm × width 45 mm
The Panasonic SF-C21 is a safety control unit that requires no programming skills; according to the manufacturer one unit does the work of four safety relay units. It meets Category 4, PL e to ISO 13849-1:2015, SIL 3 to IEC 61508 and SILCL 3 to IEC 62061. It has 2 × 4 safety inputs, 2 reset/EDM inputs, 2 × 2 PNP control outputs and 4 auxiliary outputs. A rotary switch selects one of eight preset logics certified up to Category 4, PL e; a user-customised logic is stored as logic No. 0. At 97 mm × 45 mm it fits into narrow panels.
Preset logics: overall stop, parallel muting, sequential muting, partial stop 1 and 2, two-hand control, OR control and operation mode selection. The OFF delay of control output 2 is set in ten steps from 0 to 60 s with a rotary switch. The free Configurator SF-C software customises logic, assigns auxiliary outputs and sets ON/OFF delay and muting time; customised logics are also safety-certified. Via RS-485 (MODBUS RTU), status and error history of up to 8 units can be read by a general-purpose PLC; this information cannot be used for safety control. Input filter time setting and an exit-only muting function have been added.
Panasonic SF-C21 technical specifications
| General | |
|---|---|
| Safety standards | IEC 61508-1 to 3 (SIL 3), ISO 13849-1:2015 (Category 4, PL e), IEC 62061 (SILCL 3), IEC 61131-2, IEC 61010-2-201, UL 61010-1, UL 1998 |
| EMC standards | IEC 61000-6-2, IEC 61326-3-1, EN 55011 |
| Certifications | CE, UKCA, TÜV SÜD, TÜV SÜD (USA, Canada), Korea Radio Waves Act registration |
| Safety ratings | |
| PFHd / MTTFd | 9.73×10⁻¹⁰ / 100 years or more |
| Logic selection | No.0 custom, No.1–8 preset logics (rotary switch) |
| Interlock / lockout release / EDM | incorporated |
| Electrical characteristics | |
| Supply voltage | internal and external supply: 24 V DC +10 / -15 %, ripple P-P 10 % or less |
| Current consumption | internal supply 200 mA, external supply 100 mA or less |
| Safety input (IN1–IN8) | 2 × 4 inputs; ON level 18 V / 3.5 mA, OFF level 5 V / 1.0 mA; approx. 5 mA, 4.7 kΩ |
| Startup time | 2 s or less after power on |
| Outputs and indicators | |
| Control output (OUT1–OUT4) | PNP open collector, 2 outputs × 2, max. 300 mA per output; short-circuit protected |
| Response time | OFF: 10 ms or less, ON: 100 ms or less |
| ON / OFF delay | OFF 0.0–60.0 s (0.1 s steps), ON 1–5,940 s (via software) |
| Auxiliary output (AUX1–AUX4) | PNP open collector, 1 output × 4, max. 60 mA |
| Muting indicator output | semiconductor photo MOS relay × 1, max. 60 mA |
| Communication | RS-485, MODBUS RTU, max. 100 m, 8 units (slaves) |
| Environmental | |
| Degree of protection | IP20 (IEC); must be installed in a control panel rated IP54 or higher |
| Operating temperature | -10 to +55 °C (no condensation or icing) |
| Storage temperature | -25 to +60 °C |
| Ambient humidity | 30–85 % RH |
| Shock resistance | 147 m/s² (15 G), 11 ms, X, Y and Z three times each |
| Mechanical and connection | |
| Connection | detachable spring-cage terminal blocks; USB Mini-B |
| Maximum cable length | 100 m or less |
| Enclosure material | polycarbonate / ABS polymer alloy; enclosure polycarbonate |
| Weight | net approx. 190 g, gross approx. 320 g |
Key features
- One unit replaces four safety relay units; 97 mm × 45 mm
- 8 preset logics certified up to Category 4, PL e, selected by rotary switch
- Custom logic with Configurator SF-C software without programming; custom logics are also safety-certified
- Long-life semiconductor (PNP) control and auxiliary outputs
- Status monitoring from a general-purpose PLC via RS-485 (MODBUS RTU)
- Input filter time setting and exit-only muting function
SF-C21 ordering codes
| Part number | Description |
|---|---|
| SF-C21 | safety control unit: safety input 2×4, reset/EDM input 2, control output 2×2, auxiliary output 4 |
Other Panasonic Safety Relays
- PANASONIC SF-C10 — Control unit for safety light curtains (relay output)
Models from other brands: Safety Relays
Is this safety relay right for your application?
Share the safety inputs to be connected (emergency stop, door switch, light curtain), the number of output contacts, the need for off-delayed outputs, the supply voltage and the required performance level (PL); let’s select the right unit together.
All product specifications are subject to change without notice. Validation of the safety function and the risk assessment remain the responsibility of the machine builder. Source: Panasonic Industry, https://industry.panasonic.com/global/en/products/fasys/sensor/safety/sf-c21, https://industry.panasonic.com/global/en/products/fasys/sensor/safety/number/sf-c21 (accessed 25 September 2026).