Final answer:
I/O implementation for the SLC-3 is achieved through modular I/O cards in a chassis, with data exchange facilitated by a backplane.
Step-by-step explanation:
The correct answer is option Engineering. When considering the implementation of I/O for the SLC-3, it is important to understand that this refers to a module within the Allen-Bradley SLC 500 family of programmable logic controllers (PLCs).
The I/O for an SLC-3 is typically implemented through a combination of modular I/O cards which are inserted in slots of a chassis. These modules can include digital or analog inputs and outputs, specialty modules, and communication modules.
The SLC-3 system communicates with these I/O modules using a backplane within the chassis which allows for data exchange between the processor and the I/O modules.
The setup might include racks with different capacities, potentially ranging from 4 to 16 modules per rack, depending on the complexity of the control system. It is crucial for proper system operation that these I/O modules are configured correctly using the RSLogix 500 programming software, which sets up the input and output addresses that the user's program will reference.
Technicians and engineers can monitor the data through connected human-machine interfaces (HMIs) and manipulate the control logic as necessary to achieve the desired automation outcomes in their industrial processes.
The correct answer is option A: The I/O for the SLC-3 is implemented using a combination of polling and interrupt-driven I/O. Polling involves the processor periodically checking the status of an I/O device to determine if it is ready for data transfer. Interrupt-driven I/O allows the I/O device to notify the processor when it is ready for data transfer.
For example, when a keyboard input is needed, the processor can use polling to check if any key has been pressed, and if so, read the corresponding ASCII code from the keyboard buffer.
On the other hand, if the processor needs to output data to a printer, it can use interrupt-driven I/O to send a request to the printer controller, which will then interrupt the processor when it is ready to receive data.