220-1101 Question 87
Single answerRadio-frequency identification (RFID)A warehouse uses RFID tags on inventory so employees can move boxes past a loading dock reader without stopping to scan each item individually. After a layout change, staff report that some tagged boxes are no longer detected consistently when they pass through the dock at normal speed. The tags themselves are still attached and not damaged. Which of the following is the MOST likely cause of the problem?
- A
The reader is experiencing line-of-sight blockage from the new metal shelving near the dock
- B
The RFID tags need direct physical contact with the reader to transmit inventory data
- C
The warehouse Wi-Fi access points are no longer providing DHCP addresses to the RFID tags
- D
The tags are no longer compatible because RFID requires a barcode scanner for final validation
Show answer and explanation
Correct answer: A
Explanation
This question tests practical understanding of how RFID behaves in real environments. A key advantage of RFID over barcodes is that tags can often be read without direct line-of-sight and without scanning each item individually. However, RFID performance is highly affected by the physical environment. Metal shelving, racks, doors, and nearby structures can reflect or detune RF signals, creating missed reads or inconsistent tag detection. This is a common troubleshooting issue in warehouses, retail stockrooms, and loading areas. CompTIA A+ Core 1 expects candidates to recognize RFID as a wireless identification technology distinct from barcode scanning and to understand its practical limitations, especially environmental interference. Best practices from RFID vendors and deployment guides commonly recommend evaluating antenna placement, reader positioning, and nearby metal or liquid sources when troubleshooting inconsistent reads.
- A. Correct.
Correct. RFID does not require optical line-of-sight like a barcode, but radio waves can be absorbed, reflected, or disrupted by environmental factors such as nearby metal shelving and, in some cases, liquids. In a warehouse, adding metal structures near a reader can create interference, dead spots, or altered read zones that reduce detection reliability as items pass through.
- B. Incorrect.
Incorrect. This describes a misconception about RFID. RFID is specifically useful because it does not require direct physical contact or precise alignment like some contact-based technologies. Passive RFID tags can often be read at short to moderate distances depending on the system design, reader power, antenna placement, and tag type.
- C. Incorrect.
Incorrect. Standard RFID tags do not obtain DHCP addresses. Passive RFID tags have no IP networking stack and are energized by the reader's field. Even active RFID systems do not normally rely on DHCP in the way Wi-Fi client devices do. This option confuses RFID infrastructure with wireless network client behavior.
- D. Incorrect.
Incorrect. RFID and barcodes are separate identification technologies. An RFID deployment does not require a barcode scanner to validate tags. Some organizations use both technologies in parallel for workflow reasons, but lack of a barcode scanner would not make RFID tags incompatible.