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.
Designed for robust industrial environment expansion, the Beckhoff C9900-E251 slotbox allows operators to extend compatible Beckhoff Industrial PCs with two additional plug-in card slots. This expansion unit is constructed with a fanless aluminum housing engineered specifically for space-saving control cabinet installation. It establishes a high-speed link with the host controller via a PCIe x1 interface, requiring a matching PCIe module (such as the C9900-E236 or C9900-E239) installed within the primary PC. By facilitating remote slot placement, the C9900-E251 provides flexibility in layout configuration and system hardware scaling without upgrading the primary PC chassis.
| Manufacturer | Beckhoff Automation |
| Model / Part Number | C9900-E251 |
| Product Type | Slotbox for Industrial PC expansion |
| Housing Material | Fanless aluminum housing |
| Mounting Type | Control cabinet installation |
| Expansion Slots | 2 PCI slots (supports card lengths up to 190 mm) |
| Host Interface | PCIe x1 input |
| Compatible Host Modules | Beckhoff C9900-E236 or C9900-E239 PCIe modules |
| Maximum Connection Distance | 7 meters |
| Power Supply | 24 V DC |
| Protection Rating | IP20 |
| Operating Temperature | 0 to 55 degC |
| Dimensions (W x H x D) | 94 mm x 222 mm x 132 mm (without mounting plate) |
| Weight | 1.7 kg (without plug-in cards) |
| Interface Type | Function / Description |
|---|---|
| PCIe x1 Input | Connection port to link with the host Industrial PC via compatible extension cable |
| Power Terminal | 24 V DC connection point for main operational power |
| PCI Slots (x2) | Internal slots for mounting and interfacing plug-in expansion boards |
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Returns & Warranty

Designed for robust industrial environment expansion, the Beckhoff C9900-E251 slotbox allows operators to extend compatible Beckhoff Industrial PCs with two additional plug-in card slots. This expansion unit is constructed with a fanless aluminum housing engineered specifically for space-saving control cabinet installation. It establishes a high-speed link with the host controller via a PCIe x1 interface, requiring a matching PCIe module (such as the C9900-E236 or C9900-E239) installed within the primary PC. By facilitating remote slot placement, the C9900-E251 provides flexibility in layout configuration and system hardware scaling without upgrading the primary PC chassis.
| Manufacturer | Beckhoff Automation |
| Model / Part Number | C9900-E251 |
| Product Type | Slotbox for Industrial PC expansion |
| Housing Material | Fanless aluminum housing |
| Mounting Type | Control cabinet installation |
| Expansion Slots | 2 PCI slots (supports card lengths up to 190 mm) |
| Host Interface | PCIe x1 input |
| Compatible Host Modules | Beckhoff C9900-E236 or C9900-E239 PCIe modules |
| Maximum Connection Distance | 7 meters |
| Power Supply | 24 V DC |
| Protection Rating | IP20 |
| Operating Temperature | 0 to 55 degC |
| Dimensions (W x H x D) | 94 mm x 222 mm x 132 mm (without mounting plate) |
| Weight | 1.7 kg (without plug-in cards) |
| Interface Type | Function / Description |
|---|---|
| PCIe x1 Input | Connection port to link with the host Industrial PC via compatible extension cable |
| Power Terminal | 24 V DC connection point for main operational power |
| PCI Slots (x2) | Internal slots for mounting and interfacing plug-in expansion boards |
Global Express Shipping
Returns & Warranty
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| Country of origin |
Germany
|