What Is a Programmable Logic Controller and How Does It Work
Learn how a PLC works, including scan cycle, I/O sizing, IEC 61131-3 programming, and hardware selection for ABB, Schneider, and Siemens. Shop at Stoklink.
The Siemens SIMATIC HMI KP8F PN (6AV3688-3AF37-0AX0) is a fail-safe key panel with 8 short-stroke, multi-color-LED keys and 2 PROFINET interfaces with PROFIsafe, supporting up to 1x SIL 3 or 2x SIL 2 safety circuits. It runs from 24 V DC (0.3 A), rated IP65 at the front and IP20 at the rear.
The PROFIsafe rating of 1x SIL 3 or 2x SIL 2 (single-channel) is the deciding spec for a machine's e-stop or safety-key architecture: it lets this panel carry safety-relevant emergency-stop or enabling-switch functions directly over PROFINET rather than routing separate hardwired safety circuits back to a safety PLC. The 8 parameterizable short-stroke keys with 5-color LED feedback per key double as an operator status display, useful where a full graphic HMI is unnecessary and panel space is tight. ATEX Zone 2/22 and cULus Class I Division 2 approvals extend its use to hazardous-area machine perimeters, which is not the case for a standard (non-F) KP8 panel.
Machine-side operator stations needing safety-rated emergency stop, enabling, or mode-select functions integrated into PROFINET/PROFIsafe, such as press lines, packaging cells, and machine tool control panels, including hazardous-area (ATEX Zone 2/22) installations.
| Product type designation | KP8F PN |
|---|
| With parameterizable keys | Yes |
|---|---|
| Membrane keyboard: user-definable label membrane keys | Yes |
| Function keys: Number of function keys | 8 |
| Short-stroke keys: Number of short-stroke keys | 8 |
| Expansions for operator control of the process: DP direct LEDs (LEDs as S7 output I/O) | 8; Adjustable brightness |
| Expansions for operator control of the process: Number of color modes for LED | 5; red, green, blue, yellow, white |
| Expansions for operator control of the process: Direct keys (keys as S7 input I/O) | 8 |
| Mounting type | Mounting clip |
|---|---|
| Mounting position | vertical |
| Rack mounting | No |
| Front mounting | Yes; Compatible with Extension Units dimensions |
| Rail mounting | No |
| Wall mounting/direct mounting | No |
| Mounting in portrait format possible | Yes |
| Mounting in landscape format possible | Yes |
| maximum permissible angle of inclination without external ventilation | 30°; To the front/rear |
| Number of slots for command devices and signaling units | 0 |
| Part number | 6AV3688-3AF37-0AX0 |
|---|---|
| Type designation | KP8F PN |
| Brand | Siemens |
| Condition | New, factory sealed |
| Source | Siemens and its authorised distributors |
| Warranty | Manufacturer warranty |
| Lifecycle status | Active, in production |
| EAN | 4025515079163 |
| ETIM class | EC001415 |
| eCl@ss | 27330204 |
| Type of supply voltage | DC |
|---|---|
| Rated value (DC) | 24 V; 24 V can be looped through connector, interrupted when pulled |
| permissible range, lower limit (DC) | 20.4 V |
| permissible range, upper limit (DC) | 28.8 V |
| Current consumption (rated value) | 0.3 A |
|---|
| Number of digital inputs | 8; total inputs and outputs max. 8 and 2x SIL 2 or 1x SIL 3 |
|---|---|
| Input voltage: Rated value (DC) | 24 V |
| Number of digital outputs | 8; Max. 8 inputs and outputs (total) |
|---|---|
| Short-circuit protection | Yes |
| Switching capacity of the outputs: with resistive load, max. | 100 mA |
| Output voltage: Rated value (DC) | 24 V; Non-isolated |
| Total current of the outputs: Current per channel, max. | 100 mA |
| Total current of the outputs: Current per group, max. | 800 mA |
| Number of industrial Ethernet interfaces | 2; For the construction of lines and rings without external switch |
|---|---|
| Number of PROFINET interfaces | 2; Incl. switch |
| Industrial Ethernet: Industrial Ethernet status LED | 2; Per port |
| Industrial Ethernet: Number of ports of the integrated switch | 2; Per port |
| PROFINET | Yes; also 3rd party PLC |
|---|---|
| Supports protocol for PROFINET IO | Yes |
| PROFINET CBA | No |
| IRT | Yes |
| PROFIsafe | Yes; 1x SIL 3 (two-channel) or 2x SIL 2 (single-channel) emergency stop sensors |
| PROFIBUS | No |
| EtherNet/IP | No |
| MPI | No |
| AS-Interface | No |
| EIB/KNX | No |
| Protocols (Ethernet): TCP/IP | No |
| Redundancy mode Media redundancy: MRP | Yes |
| Further protocols: AS-Interface Safety at Work | No |
| Further protocols: CAN | No |
| Further protocols: Data-Highway | No |
| Further protocols: DeviceNet | No |
| Further protocols: DeviceNet Safety | No |
| Further protocols: Foundation Fieldbus | No |
| Further protocols: INTERBUS | No |
| Further protocols: INTERBUS-Safety | No |
| Further protocols: Local Operating Network | No |
| Further protocols: MODBUS | No |
| Further protocols: SafetyBUS p | No |
| Further protocols: SERCOS | No |
| Further protocols: SUCOnet | No |
| Further protocols: other bus systems | No |
| Illuminant test | Yes; During switch on |
|---|---|
| Key and signal lamp test | Yes; automatically when switching on |
| Emission of radio interference acc. to EN 55 011: Limit class A, for use in industrial areas | Yes; Group 1, measured at a distance of 10 m |
|---|
| IP (at the front) | IP65 |
|---|---|
| IP (rear) | IP20 |
| NEMA (front): Enclosure Type 4 at the front | No |
| NEMA (front): Enclosure Type 4x at the front | Yes; Incl. NEMA12 |
| CE mark | Yes |
|---|---|
| cULus | Yes |
| RCM (formerly C-TICK) | Yes |
| KC approval | Yes |
| EAC (formerly Gost-R) | Yes |
| CCC | No; not necessary |
| Suitable for safety functions | Yes |
| Use in hazardous areas: ATEX Zone 2 | Yes |
| Use in hazardous areas: ATEX Zone 22 | Yes |
| Use in hazardous areas: cULus Class I Zone 1 | No |
| Use in hazardous areas: cULus Class I Zone 2, Division 2 | Yes |
| Use in hazardous areas: FM Class I Division 2 | Yes |
| Marine approval: Germanischer Lloyd (GL) | No |
| Marine approval: American Bureau of Shipping (ABS) | No |
| Marine approval: Bureau Veritas (BV) | No |
| Marine approval: Det Norske Veritas (DNV) | No |
| Marine approval: Lloyds Register of Shipping (LRS) | No |
| Marine approval: Nippon Kaiji Kyokai (Class NK) | No |
| Marine approval: Polski Rejestr Statkow (PRS) | No |
| Ambient temperature during operation: min. | 0 °C |
|---|---|
| Ambient temperature during operation: max. Operation (vertical installation) | 55 °C |
| Ambient temperature during operation: For vertical installation, min. | 0 °C |
| Ambient temperature during operation: At maximum tilt angle, min. | 0 °C |
| Ambient temperature during storage/transportation: min. | -20 °C |
| Ambient temperature during storage/transportation: max. | 60 °C |
| Relative humidity: Operation, max. | 95 %; no condensation |
| Configuration software: STEP 7 Basic (TIA Portal) | Yes |
|---|---|
| Configuration software: STEP 7 Professional (TIA Portal) | Yes |
| Process coupling: S7-1200 | Yes; with ET 200pro CPU and ET 200S CPU |
|---|---|
| Process coupling: S7-1500 | Yes |
| Process coupling: S7-200 | No |
| Process coupling: S7-300/400 | Yes; with F-CPU: STEP 7 V11 SP1 (or higher) and Safety V11 (or higher) or SIMATIC STEP 7 Basic V11 (or higher) |
| Process coupling: LOGO! | No |
| Process coupling: WinAC | Yes |
| Process coupling: SINUMERIK | No |
| Process coupling: SIMOTION | No |
| Process coupling: Allen Bradley (EtherNet/IP) | No |
| Process coupling: Allen Bradley (DF1) | No |
| Process coupling: Mitsubishi (MC TCP/IP) | No |
| Process coupling: Mitsubishi (FX) | No |
| Process coupling: OMRON (FINS TCP) | No |
| Process coupling: OMRON (Host Link) | No |
| Process coupling: Modicon (Modbus TCP/IP) | No |
| Process coupling: Modicon (Modbus RTU) | No |
| Enclosure material (front): Plastic | Yes |
|---|---|
| Enclosure material (front): Aluminum | No |
| Enclosure material (front): Stainless steel | No |
| Service life: Short-stroke keys (in switching cycles) | 1 500 000 |
| Service life: LEDs (ON period) | 100 % |
| Width of the housing front | 98 mm |
|---|---|
| Height of housing front | 155 mm |
| Mounting cutout, width | 67.7 mm; Max. thickness of mounting plate 2 - 6 mm |
| Mounting cutout, height | 129.7 mm |
| mounting depth | 49 mm; Incl. angled SIMATIC Ethernet connector |
| Weight (without packaging) | 280 g |
|---|
| Net weight | 0.324 kg |
|---|---|
| Country of origin | DE |
| Shipping weight | 0.824 kg |
| Ships from | Türkiye |
| Dispatch | 13 Nov |
| Stock | Low stock |
Source: manufacturer data · Last verified: 01 Nov 2026
No documents are on file for this part yet.
Ask us for the datasheetThe rated current of KP8F PN is 0.3 A.
The rated operational voltage of KP8F PN is 24; 24 can be looped through connector, interrupted when pulled V AC.
The tariff (HS) code on file for KP8F PN is 85371098.
The EAN (GTIN) of KP8F PN is 4025515079163.
KP8F PN ships from Türkiye. Shipping calculated at checkout · import duties and taxes paid on arrival. Stock items are dispatched within 1–2 business days.
Learn how a PLC works, including scan cycle, I/O sizing, IEC 61131-3 programming, and hardware selection for ABB, Schneider, and Siemens. Shop at Stoklink.
Compare ABB, Siemens, and Schneider Electric across motor control, energy efficiency, installation, support, and power distribution. Shop at Stoklink.
Contactors deliver safe, reliable motor control and automation switching for industrial systems, lighting, pumps, and heating loads. Shop at Stoklink.