Allen-Bradley 1791D-8B8P CompactBlock I/O Combination Base Block
The Allen-Bradley 1791D-8B8P is a DeviceNet-compatible CompactBlock I/O combination base module designed for distributed industrial automation architectures. This unit integrates internal I/O circuits, a built-in power supply, and a DeviceNet adapter into a single housing, streamlining panel space and reducing external wiring requirements for discrete control tasks.
Network Communication and Architecture
Operating as a slave device on a DeviceNet network, this module supports polled, cyclic, and change-of-state data transfer modes. It features automatic baud rate detection to seamlessly match network communication speeds configured by the master scanner.
Discrete Input and Output Channels
The module provides 8 sinking discrete inputs and 8 sourcing discrete outputs to interface with various field sensors and actuators. Input filtering helps minimize false triggers caused by electrical noise or contact bounce, while output channels include built-in short-circuit protection.
Power Requirements and Mounting
Communication power is supplied directly via the DeviceNet network, whereas inputs and outputs require an independent 24 VDC external power source. The compact base block mounts securely onto standard DIN rails or directly onto flat industrial control panels.
Technical Parameters
| Parameter | Specification |
|---|---|
| Brand | Allen-Bradley |
| Model | 1791D-8B8P |
| Product Line | CompactBlock I/O |
| Network Protocol | DeviceNet |
| Inputs per Block | 8 (Sinking) |
| Outputs per Block | 8 (Sourcing) |
| Output Current | 0.5 A maximum per output |
| External Power Supply | 24 VDC |
| Enclosure Rating | IEC IP20 |
| Weight | 0.35 lbs (0.16 kg) |
Frequently Asked Questions
Q: What type of external power supply is required for the input and output channels?A: The inputs and outputs require an independent 24 VDC external power source separate from the DeviceNet network power.
Q: How does the module communicate with the master controller?A: It operates as a slave device on a DeviceNet network, supporting polled, cyclic, and change-of-state data exchanges configured via the scanner module.
Q: What action does the module take if the DeviceNet network connection fails?A: If the network connection drops or the scanner enters a fault state, the module transitions to a fault state and resets its outputs by default.
Allen-Bradley 1791D-8B8P CompactBlock I/O Combination Base Block
Allen-Bradley 1791D-8B8P CompactBlock I/O Combination Base Block
The Allen-Bradley 1791D-8B8P is a DeviceNet-compatible CompactBlock I/O combination base module designed for distributed industrial automation architectures. This unit integrates internal I/O circuits, a built-in power supply, and a DeviceNet adapter into a single housing, streamlining panel space and reducing external wiring requirements for discrete control tasks.
Network Communication and Architecture
Operating as a slave device on a DeviceNet network, this module supports polled, cyclic, and change-of-state data transfer modes. It features automatic baud rate detection to seamlessly match network communication speeds configured by the master scanner.
Discrete Input and Output Channels
The module provides 8 sinking discrete inputs and 8 sourcing discrete outputs to interface with various field sensors and actuators. Input filtering helps minimize false triggers caused by electrical noise or contact bounce, while output channels include built-in short-circuit protection.
Power Requirements and Mounting
Communication power is supplied directly via the DeviceNet network, whereas inputs and outputs require an independent 24 VDC external power source. The compact base block mounts securely onto standard DIN rails or directly onto flat industrial control panels.
Technical Parameters
| Parameter | Specification |
|---|---|
| Brand | Allen-Bradley |
| Model | 1791D-8B8P |
| Product Line | CompactBlock I/O |
| Network Protocol | DeviceNet |
| Inputs per Block | 8 (Sinking) |
| Outputs per Block | 8 (Sourcing) |
| Output Current | 0.5 A maximum per output |
| External Power Supply | 24 VDC |
| Enclosure Rating | IEC IP20 |
| Weight | 0.35 lbs (0.16 kg) |
Frequently Asked Questions
Q: What type of external power supply is required for the input and output channels?A: The inputs and outputs require an independent 24 VDC external power source separate from the DeviceNet network power.
Q: How does the module communicate with the master controller?A: It operates as a slave device on a DeviceNet network, supporting polled, cyclic, and change-of-state data exchanges configured via the scanner module.
Q: What action does the module take if the DeviceNet network connection fails?A: If the network connection drops or the scanner enters a fault state, the module transitions to a fault state and resets its outputs by default.
