Implementing 3-Switch XOR Ladder Logic with Internal Bit
Implement a 3-SPST switch XOR light circuit in LogixPro or RSLogix 500 using an internal relay bit. Includes truth tables, boolean equations, and verified.
The BECKHOFF IP2021-B318 is a high-performance, decentralized Fieldbus Box designed to interface digital output signals directly within a PROFIBUS DP network. Engineered for direct installation in the field, this module bypasses the need for a protective control cabinet, significantly reducing wiring overhead and simplifying system architecture.
With 8 digital output channels, the BECKHOFF IP2021-B318 delivers up to 2 A per channel at 24 V DC. This high current-carrying capacity makes the device highly suited for driving medium-power loads such as hydraulic and pneumatic solenoids, contactors, indicators, and smaller actuators.
The module is constructed for deployment in demanding industrial environments, featuring an IP67 physical protection rating. It utilizes secure M8 screw connectors for signal I/O and features an integrated PROFIBUS T-connector to facilitate straightforward bus daisy-chaining and clean physical cable routing.
| Parameter | Specification |
|---|---|
| Manufacturer | BECKHOFF |
| Model | IP2021-B318 |
| Product Type | Fieldbus Box |
| Protocol | PROFIBUS DP |
| Number of Outputs | 8 digital outputs |
| Nominal Voltage | 24 V DC (-15% / +20%) |
| Maximum Output Current | 2.0 A per channel (short-circuit proof) |
| I/O Connection Method | M8 screw type |
| Bus Connection | Integrated T-connector |
| Protection Class | IP67 |
| Operating Temperature | 0 degC to +55 degC |
| Storage Temperature | -25 degC to +85 degC |
When replacing an active BECKHOFF IP2021-B318, always record the physical PROFIBUS node address configuration from the existing hardware. Set the matching address on the replacement unit prior to restoring power. Ensure all M8 connections are clean, dry, and securely tightened to prevent moisture ingress or connection failure during operation.
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Returns & Warranty

The BECKHOFF IP2021-B318 is a high-performance, decentralized Fieldbus Box designed to interface digital output signals directly within a PROFIBUS DP network. Engineered for direct installation in the field, this module bypasses the need for a protective control cabinet, significantly reducing wiring overhead and simplifying system architecture.
With 8 digital output channels, the BECKHOFF IP2021-B318 delivers up to 2 A per channel at 24 V DC. This high current-carrying capacity makes the device highly suited for driving medium-power loads such as hydraulic and pneumatic solenoids, contactors, indicators, and smaller actuators.
The module is constructed for deployment in demanding industrial environments, featuring an IP67 physical protection rating. It utilizes secure M8 screw connectors for signal I/O and features an integrated PROFIBUS T-connector to facilitate straightforward bus daisy-chaining and clean physical cable routing.
| Parameter | Specification |
|---|---|
| Manufacturer | BECKHOFF |
| Model | IP2021-B318 |
| Product Type | Fieldbus Box |
| Protocol | PROFIBUS DP |
| Number of Outputs | 8 digital outputs |
| Nominal Voltage | 24 V DC (-15% / +20%) |
| Maximum Output Current | 2.0 A per channel (short-circuit proof) |
| I/O Connection Method | M8 screw type |
| Bus Connection | Integrated T-connector |
| Protection Class | IP67 |
| Operating Temperature | 0 degC to +55 degC |
| Storage Temperature | -25 degC to +85 degC |
When replacing an active BECKHOFF IP2021-B318, always record the physical PROFIBUS node address configuration from the existing hardware. Set the matching address on the replacement unit prior to restoring power. Ensure all M8 connections are clean, dry, and securely tightened to prevent moisture ingress or connection failure during operation.
Global Express Shipping
Returns & Warranty
Orders are processed and delivered Monday-Friday (excluding public holidays).
For full eligibility, restocking fees, and international return details, please view our official Refund & Return Policy .
| Country of origin |
Germany
|