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.
Facilitating robust physical human-machine interface interaction, the Beckhoff C9900-E805 mounts directly to the right side of CP6x21-00xx and CP7x21-00xx Control Panels and Panel PCs with 15-inch displays. This push-button extension provides operators with tactile physical controls alongside the touchscreen interface. Designed for environments requiring high mechanical feedback, the unit integrates twelve customizable square push-buttons and an integrated, directly wireable emergency stop device. By offering two parallel communication paths—integrated serial digital transmission via CP-Link or USB, alongside secondary direct-wiring physical terminals—this hardware extension ensures critical machine execution commands remain highly reliable and deterministically wired back to safety controllers or PLC input cards.
| Parameter | Specification Value |
|---|---|
| Manufacturer | Beckhoff Automation |
| Model Reference | C9900-E805 |
| Product Lifecycle Phase | Service Phase (Legacy/Replacement Support) |
| Display Size Compatibility | 15-inch displays (without keyboard integrations) |
| Control Panel Models | CP6x21-00xx, CP7x21-00xx Series |
| Push-Button Element type | Siemens Signum, Square 30 x 30 mm |
| Total Configurable Keys | 12 Keys with integrated illumination |
| Emergency Stop Element | 1x Siemens Signum mechanical push-lock turn-reset button |
| Communication Protocol | CP-Link or USB (for primary key state transmission and LED control) |
| Parallel Contact Interface | Terminal strip for direct point-to-point hardwiring (second NO contact) |
| Emergency Stop Interface | Direct hardwired connection (independent of serial bus) |
| Country of Origin | Germany |
| Shipping Weight (Calculated) | 5.00 kg |
| Interface Location | Interface Type | Functional Assignment |
|---|---|---|
| Internal Bus Port | CP-Link / USB Connector | Main interface backplane connection to host Control Panel logic board for key states and LED control. |
| Rear Access Terminal Strip | Screw Clamp/Push-In Terminal Row | Direct physical access to secondary normally-open (NO) contacts for customized safety or legacy PLC wiring. |
| E-Stop Dedicated Terminal | Independent Terminal Block | Isolated dual-contact routing directly to safety monitoring relays or fail-safe inputs. |
The C9900-E805 unit is tailored strictly for 15-inch Control Panels. It cannot be retrofitted to smaller (e.g., 12-inch) or larger (e.g., 19-inch) display housings due to structural mounting spacing and cable harnesses. Since this is in its Service Phase, existing systems running CP6x21 or CP7x21 hardware should maintain a backup spare of this model. If transitioning to newer CP2xxx or CP3xxx panels, a different generation of push-button extensions is required, as the electrical interface signals differ.
While the push-buttons are transmitted digitally via CP-Link or USB under normal operation, never rely on the USB or CP-Link serial communication pathway for emergency isolation. The emergency stop button must always be hardwired directly from its rear contacts to safety-rated safety relays (such as EL6900 or dedicated safety modules) to meet SIL 3/Category 4 safety directives.
When configuring the auxiliary terminal rows for dry contact wiring, ensure control wiring does not run parallel to high-voltage, high-frequency motor cables to prevent EMI. Grounding the frame of the associated CP6xxx/CP7xxx panel via the ground stud is mandatory for the internal digital encoders to operate reliably without signal dropouts.
Isolate and de-energize all power sources feed to the primary Control Panel or Panel PC and auxiliary terminal strip connections before mechanical integration. Ensure the field bus line is inactive. Discharge electrostatic buildup by grounding yourself to the machine frame before making connections to the internal components.
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Facilitating robust physical human-machine interface interaction, the Beckhoff C9900-E805 mounts directly to the right side of CP6x21-00xx and CP7x21-00xx Control Panels and Panel PCs with 15-inch displays. This push-button extension provides operators with tactile physical controls alongside the touchscreen interface. Designed for environments requiring high mechanical feedback, the unit integrates twelve customizable square push-buttons and an integrated, directly wireable emergency stop device. By offering two parallel communication paths—integrated serial digital transmission via CP-Link or USB, alongside secondary direct-wiring physical terminals—this hardware extension ensures critical machine execution commands remain highly reliable and deterministically wired back to safety controllers or PLC input cards.
| Parameter | Specification Value |
|---|---|
| Manufacturer | Beckhoff Automation |
| Model Reference | C9900-E805 |
| Product Lifecycle Phase | Service Phase (Legacy/Replacement Support) |
| Display Size Compatibility | 15-inch displays (without keyboard integrations) |
| Control Panel Models | CP6x21-00xx, CP7x21-00xx Series |
| Push-Button Element type | Siemens Signum, Square 30 x 30 mm |
| Total Configurable Keys | 12 Keys with integrated illumination |
| Emergency Stop Element | 1x Siemens Signum mechanical push-lock turn-reset button |
| Communication Protocol | CP-Link or USB (for primary key state transmission and LED control) |
| Parallel Contact Interface | Terminal strip for direct point-to-point hardwiring (second NO contact) |
| Emergency Stop Interface | Direct hardwired connection (independent of serial bus) |
| Country of Origin | Germany |
| Shipping Weight (Calculated) | 5.00 kg |
| Interface Location | Interface Type | Functional Assignment |
|---|---|---|
| Internal Bus Port | CP-Link / USB Connector | Main interface backplane connection to host Control Panel logic board for key states and LED control. |
| Rear Access Terminal Strip | Screw Clamp/Push-In Terminal Row | Direct physical access to secondary normally-open (NO) contacts for customized safety or legacy PLC wiring. |
| E-Stop Dedicated Terminal | Independent Terminal Block | Isolated dual-contact routing directly to safety monitoring relays or fail-safe inputs. |
The C9900-E805 unit is tailored strictly for 15-inch Control Panels. It cannot be retrofitted to smaller (e.g., 12-inch) or larger (e.g., 19-inch) display housings due to structural mounting spacing and cable harnesses. Since this is in its Service Phase, existing systems running CP6x21 or CP7x21 hardware should maintain a backup spare of this model. If transitioning to newer CP2xxx or CP3xxx panels, a different generation of push-button extensions is required, as the electrical interface signals differ.
While the push-buttons are transmitted digitally via CP-Link or USB under normal operation, never rely on the USB or CP-Link serial communication pathway for emergency isolation. The emergency stop button must always be hardwired directly from its rear contacts to safety-rated safety relays (such as EL6900 or dedicated safety modules) to meet SIL 3/Category 4 safety directives.
When configuring the auxiliary terminal rows for dry contact wiring, ensure control wiring does not run parallel to high-voltage, high-frequency motor cables to prevent EMI. Grounding the frame of the associated CP6xxx/CP7xxx panel via the ground stud is mandatory for the internal digital encoders to operate reliably without signal dropouts.
Isolate and de-energize all power sources feed to the primary Control Panel or Panel PC and auxiliary terminal strip connections before mechanical integration. Ensure the field bus line is inactive. Discharge electrostatic buildup by grounding yourself to the machine frame before making connections to the internal components.
Global Express Shipping
Returns & Warranty
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| Country of origin |
Germany
|