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.
Providing reliable timing control within industrial control panels, the Omron H3CR-A8E 100/240VC solid-state timer is engineered for precision sequencing and delay operations. This 8-pin model features a unique output configuration combining a time-limit SPDT contact with an instantaneous SPDT contact, allowing for immediate secondary circuit activation upon power-up alongside delayed system execution. With its broad operating range and robust electrical design, it serves as a core coordination component in motor starters, conveyor systems, and sequential machine logic.
| Parameter | Specification Value |
|---|---|
| Manufacturer | Omron |
| Model Reference | H3CR-A8E 100/240VC |
| Supply Voltage | 100 to 240 VAC (50/60 Hz) |
| Pin Count | 8 Pins (Octal Base) |
| Output Type | SPDT Time-limit (1c) + SPDT Instantaneous (1c) |
| Contact Rating (Resistive) | 5 A at 250 VAC / 30 VDC |
| Time Setting Range | 0.05 s to 300 h (selectable) |
| Reset Time | 0.1 s maximum |
| Ambient Operating Temperature | -10 to 55 degC (with no icing) |
| Shipping Weight (Calculated) | 0.25 kg |
| Package Dimensions (Calculated) | 100 mm x 60 mm x 60 mm |
| Terminal Pin | Function / Circuit Assignment |
|---|---|
| Pin 2 | Power Supply Input (L1 / Neutral Phase) |
| Pin 7 | Power Supply Input (L2 / Line Phase) |
| Pin 1 | Instantaneous Contact - Common (COM) |
| Pin 3 | Instantaneous Contact - Normally Open (NO) |
| Pin 4 | Instantaneous Contact - Normally Closed (NC) |
| Pin 8 | Time-Limit Contact - Common (COM) |
| Pin 6 | Time-Limit Contact - Normally Open (NO) |
| Pin 5 | Time-Limit Contact - Normally Closed (NC) |
The H3CR-A8E model is specifically chosen when a fast bypass or control path initialization is required alongside a delayed circuit. If replacing this unit with a standard H3CR-A8, note that the standard A8 model utilizes both SPDT contacts as time-limit delayed outputs. Substituting an A8E with an A8 without modifying the terminal base wiring will disable instantaneous functionality, causing interlocking or immediate auxiliary component startup to fail.
When switching inductive loads such as solenoid valves or heavy contactor coils, ensure that external surge suppressors (RC networks for AC, snubbing diodes for DC) are placed across the load. Switching unsuppressed inductive loads leads to high contact arcing, drastically reducing the H3CR-A8E’s internal relays' life expectancy and inducing EMI into neighboring PLC input modules.
Always utilize Omron-approved sockets (such as P2CF-08 for surface/DIN rail mounting, or P3G-08 for back-connecting panel mounts). Maintain terminal screw torques between 0.78 and 1.18 N-m to prevent thread stripping while ensuring vibration-proof mechanical connection of field conductors.
De-energize all power feeding the socket and adjacent wiring panels before inserting, removing, or setting the H3CR-A8E timer unit. Failure to observe this safety measure can result in severe shock hazard, terminal tracking, or destruction of internal electronic components.
Global Express Shipping
Returns & Warranty

Providing reliable timing control within industrial control panels, the Omron H3CR-A8E 100/240VC solid-state timer is engineered for precision sequencing and delay operations. This 8-pin model features a unique output configuration combining a time-limit SPDT contact with an instantaneous SPDT contact, allowing for immediate secondary circuit activation upon power-up alongside delayed system execution. With its broad operating range and robust electrical design, it serves as a core coordination component in motor starters, conveyor systems, and sequential machine logic.
| Parameter | Specification Value |
|---|---|
| Manufacturer | Omron |
| Model Reference | H3CR-A8E 100/240VC |
| Supply Voltage | 100 to 240 VAC (50/60 Hz) |
| Pin Count | 8 Pins (Octal Base) |
| Output Type | SPDT Time-limit (1c) + SPDT Instantaneous (1c) |
| Contact Rating (Resistive) | 5 A at 250 VAC / 30 VDC |
| Time Setting Range | 0.05 s to 300 h (selectable) |
| Reset Time | 0.1 s maximum |
| Ambient Operating Temperature | -10 to 55 degC (with no icing) |
| Shipping Weight (Calculated) | 0.25 kg |
| Package Dimensions (Calculated) | 100 mm x 60 mm x 60 mm |
| Terminal Pin | Function / Circuit Assignment |
|---|---|
| Pin 2 | Power Supply Input (L1 / Neutral Phase) |
| Pin 7 | Power Supply Input (L2 / Line Phase) |
| Pin 1 | Instantaneous Contact - Common (COM) |
| Pin 3 | Instantaneous Contact - Normally Open (NO) |
| Pin 4 | Instantaneous Contact - Normally Closed (NC) |
| Pin 8 | Time-Limit Contact - Common (COM) |
| Pin 6 | Time-Limit Contact - Normally Open (NO) |
| Pin 5 | Time-Limit Contact - Normally Closed (NC) |
The H3CR-A8E model is specifically chosen when a fast bypass or control path initialization is required alongside a delayed circuit. If replacing this unit with a standard H3CR-A8, note that the standard A8 model utilizes both SPDT contacts as time-limit delayed outputs. Substituting an A8E with an A8 without modifying the terminal base wiring will disable instantaneous functionality, causing interlocking or immediate auxiliary component startup to fail.
When switching inductive loads such as solenoid valves or heavy contactor coils, ensure that external surge suppressors (RC networks for AC, snubbing diodes for DC) are placed across the load. Switching unsuppressed inductive loads leads to high contact arcing, drastically reducing the H3CR-A8E’s internal relays' life expectancy and inducing EMI into neighboring PLC input modules.
Always utilize Omron-approved sockets (such as P2CF-08 for surface/DIN rail mounting, or P3G-08 for back-connecting panel mounts). Maintain terminal screw torques between 0.78 and 1.18 N-m to prevent thread stripping while ensuring vibration-proof mechanical connection of field conductors.
De-energize all power feeding the socket and adjacent wiring panels before inserting, removing, or setting the H3CR-A8E timer unit. Failure to observe this safety measure can result in severe shock hazard, terminal tracking, or destruction of internal electronic components.
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 |
Japan
|