Description
The BECKHOFF KS5121 is a specialized Bus Terminal with pluggable wiring designed to serve as an incremental encoder interface with an integrated electronic camshaft controller. Operating within the Beckhoff K-bus system, this module enables precise, high-speed acquisition and evaluation of 24 V DC incremental encoder signals in demanding industrial positioning applications.
The terminal supports a single incremental encoder channel with A, B, latch, and gate connections, paired with four programmable 24 V DC outputs. It features a 16-bit binary counter and handles a high limit frequency of up to 1,000,000 increments per second when utilizing 4-fold evaluation. Fast output switching times of less than 100 microseconds ensure rapid response to encoder position changes, making it highly effective for real-time cam-switching and synchronization tasks.
A key feature of the KS series is the pluggable wiring level. The BECKHOFF KS5121 allows the terminal housing to be easily detached from the wiring block, enabling rapid module replacement during maintenance without requiring manual rewiring. This minimizes installation errors and significantly reduces machine downtime during servicing.
Features
- Single-channel 24 V DC incremental encoder interface with A, B, latch, and gate connections
- Four programmable 24 V DC outputs with fast switching times under 100 microseconds
- Integrated electronic camshaft controller function for position-dependent output triggering
- High-speed 16-bit binary counter with up to 1,000,000 increments/s under 4-fold evaluation
- Pluggable connection level (KS series) for simplified wiring, maintenance, and replacement
- Direct integration into standard K-bus backplane systems
- Status LEDs for clear channel diagnostic feedback and operational states
Applications
- Rotary positioning systems requiring rapid, hardware-based camshaft switching
- High-speed packaging, labeling, and sorting machines
- Material handling and continuous-path positioning control systems
- Direct integration of encoder feedback into K-bus-based programmable logic controllers
Technical Specifications
| Parameter |
Specification |
| Manufacturer |
BECKHOFF |
| Exact Model |
KS5121 |
| Product Type |
Bus Terminal (Incremental Encoder Interface) |
| Number of Channels |
1 incremental encoder input, 4 outputs |
| Encoder Inputs |
A, B, latch, gate |
| Encoder Voltage Supply |
24 V DC |
| Output Voltage |
24 V DC |
| Output Current |
0.5 A |
| Counter Depth |
16-bit binary |
| Limit Frequency |
1,000,000 increments/s (with 4-fold evaluation) |
| Switching Speed |
Less than 100 microseconds |
| Special Functionality |
Electronic camshaft controller |
| Power Supply |
24 V DC (-15% / +20%) |
| Current Consumption (K-bus) |
Typically 60 mA |
| Current Consumption (Power Contacts) |
Typically 30 mA + load |
| Process Image Bit Width |
Input/Output: 2 x 16-bit data, 2 x 8-bit control/status |
| Connection Technology |
Pluggable spring-cage connection |
| Conductor Cross-section (Solid/Stranded) |
0.08 to 1.5 mm² (AWG 28...16) |
| Conductor Cross-section (Fine-stranded) |
0.14 to 1.5 mm² (AWG 26...16) |
| Stripping Length |
8 to 9 mm |
| Operating Temperature |
0 degC to +55 degC |
| Storage Temperature |
-25 degC to +85 degC |
| Relative Humidity |
95%, non-condensing |
| Protection Class |
IP20 |
| Dimensions (W x H x D) |
24 mm x 100 mm x 68 mm |
| Approvals |
CE, UL, ATEX (II 3 G Ex nA IIC T4 Gc) |
Installation Guidelines
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Power De-energization: Always isolate and turn off all power sources (system and field-side supplies) before commencing terminal installation, wiring, or removal.
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DIN Rail Mounting: Securely snap the terminal onto a standard 35 mm DIN rail (conforming to EN 60715) using the integrated locking mechanism. Ensure proper side-by-side coupling with neighboring K-bus terminals using the double slot-and-key design.
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Wiring Setup: Strip terminal conductors to the specified 8–9 mm length. Use a small screwdriver to actuate the tension clamps on the pluggable connector blocks, inserting the wire before releasing the clamp.
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Pluggable Block Insertion: Once wired, firmly insert the pluggable connection block into the KS5121 terminal body until it locks into place.
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K-bus Check: Connect the end terminal (typically a KL9010) at the end of the Bus Terminal assembly to ensure the integrity of the K-bus communication loop.
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Initial Commissioning: Apply K-bus power and configuration via your controller software (such as TwinCAT) to test encoder feedback and output switching paths.
Replacement Recommendations
When replacing an existing BECKHOFF KS5121 terminal, there is no need to disconnect individual field wires. Disengage the pluggable wiring blocks from the front of the failing unit, release the terminal from the DIN rail, mount the replacement KS5121 module, and firmly snap the pre-wired blocks back into the new terminal interface. Ensure the K-bus parameters match the system profile in the master configuration.