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 ER1819-0021 is a high-density, IP67-rated EtherCAT Box designed for direct machine mounting outside of traditional control cabinets. This digital input module is engineered to acquire binary control signals from the physical process level and transmit them reliably to the controller over high-speed EtherCAT. Housed in a zinc die-cast casing, it provides reliable protection against moisture, dust, and mechanical stress in harsh industrial automation environments.
This module features 16 digital inputs configured with standard M8 connections suitable for three-wire sensors. The inputs conform to the EN 61131-2 Type 1/3 specification and integrate a fast 10-microsecond input filter to ensure swift and accurate signal transition capture. The compact, decentralized architecture reduces cabling footprint, simplifies field wiring, and optimizes communication performance direct to the machine level.
| Manufacturer | BECKHOFF |
| Model | ER1819-0021 |
| Housing Material | Zinc die-cast |
| Protection Rating | IP65/IP66/IP67 (conforms to EN 60529) |
| Dimensions (W x H x D) | 60 mm x 126 mm x 26.5 mm |
| Weight | approx. 450 g |
| Number of Inputs | 16 |
| Input Connection Type | M8 x 1, 3-pin, A-coded |
| Input Specification | EN 61131-2, type 1/3 |
| Nominal Input Voltage | 24 V DC (-15% / +20%) |
| "0" Signal Voltage | -3 to +5 V (EN 61131-2, type 3) |
| "1" Signal Voltage | 11 to 30 V (EN 61131-2, type 3) |
| Input Current | typ. 3 mA (EN 61131-2, type 3) |
| Input Filter | 10 microseconds |
| Sensor Supply | From control voltage (Us), max. 0.5 A, short-circuit proof in total |
| Protocol | EtherCAT |
| Bus Interface | 2 x M8 socket, shielded, screw type |
| Power Supply Connection | Feed: 1 x M8 male, 4-pin; Downstream: 1 x M8 female, 4-pin |
| Current Consumption (Us) | 130 mA (excluding sensor current) |
| Electrical Isolation | 500 V |
| Distributed Clocks | No |
| Operating Temperature | -25 to +60 degC |
| Storage Temperature | -40 to +85 degC |
| Vibration/Shock Resistance | Conforms to EN 60068-2-6 / EN 60068-2-27 |
| EMC Immunity/Emission | Conforms to EN 61000-6-2 / EN 61000-6-4 |
| Approvals/Markings | CE, UL |
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Returns & Warranty

The BECKHOFF ER1819-0021 is a high-density, IP67-rated EtherCAT Box designed for direct machine mounting outside of traditional control cabinets. This digital input module is engineered to acquire binary control signals from the physical process level and transmit them reliably to the controller over high-speed EtherCAT. Housed in a zinc die-cast casing, it provides reliable protection against moisture, dust, and mechanical stress in harsh industrial automation environments.
This module features 16 digital inputs configured with standard M8 connections suitable for three-wire sensors. The inputs conform to the EN 61131-2 Type 1/3 specification and integrate a fast 10-microsecond input filter to ensure swift and accurate signal transition capture. The compact, decentralized architecture reduces cabling footprint, simplifies field wiring, and optimizes communication performance direct to the machine level.
| Manufacturer | BECKHOFF |
| Model | ER1819-0021 |
| Housing Material | Zinc die-cast |
| Protection Rating | IP65/IP66/IP67 (conforms to EN 60529) |
| Dimensions (W x H x D) | 60 mm x 126 mm x 26.5 mm |
| Weight | approx. 450 g |
| Number of Inputs | 16 |
| Input Connection Type | M8 x 1, 3-pin, A-coded |
| Input Specification | EN 61131-2, type 1/3 |
| Nominal Input Voltage | 24 V DC (-15% / +20%) |
| "0" Signal Voltage | -3 to +5 V (EN 61131-2, type 3) |
| "1" Signal Voltage | 11 to 30 V (EN 61131-2, type 3) |
| Input Current | typ. 3 mA (EN 61131-2, type 3) |
| Input Filter | 10 microseconds |
| Sensor Supply | From control voltage (Us), max. 0.5 A, short-circuit proof in total |
| Protocol | EtherCAT |
| Bus Interface | 2 x M8 socket, shielded, screw type |
| Power Supply Connection | Feed: 1 x M8 male, 4-pin; Downstream: 1 x M8 female, 4-pin |
| Current Consumption (Us) | 130 mA (excluding sensor current) |
| Electrical Isolation | 500 V |
| Distributed Clocks | No |
| Operating Temperature | -25 to +60 degC |
| Storage Temperature | -40 to +85 degC |
| Vibration/Shock Resistance | Conforms to EN 60068-2-6 / EN 60068-2-27 |
| EMC Immunity/Emission | Conforms to EN 61000-6-2 / EN 61000-6-4 |
| Approvals/Markings | CE, UL |
Global Express Shipping
Returns & Warranty
Orders are processed and delivered Monday-Friday (excluding public holidays).
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| Country of origin |
Germany
|