220-1101 Question 228
Single answerDB9A technician is connecting a legacy serial UPS management cable to an older workstation so monitoring software can communicate with the UPS during power events. The UPS cable ends in a 9-pin D-sub connector, but the workstation has several different ports available. Which port on the workstation should the technician use?
- A
The DB9 serial COM port
- B
The HD15 VGA port
- C
The RJ45 Ethernet port
- D
The USB Type-B port
Show answer and explanation
Correct answer: A
Explanation
This question tests recognition and practical use of a DB9 connector in a real support scenario. In A+ Core 1, candidates should be able to identify common connector types and match them to their functions. A DB9 connector is typically used for RS-232 serial communication and is commonly referred to as a serial or COM port connection in PC support contexts. By contrast, HD15 is for VGA video, RJ45 is for Ethernet networking, and USB Type-B is for USB peripheral connections. CompTIA A+ objectives covering connectors, ports, and peripheral interfaces emphasize distinguishing visually similar connectors and selecting the correct port for the device being installed.
- A. Correct.
Correct. A DB9 connector is commonly associated with an RS-232 serial connection used for COM ports on legacy PCs and peripherals. UPS management cables, serial consoles, modems, and some older industrial devices often use this type of connector for serial communication.
- B. Incorrect.
Incorrect. An HD15 connector is the standard 15-pin VGA video connector used for analog display output, not serial data communication. A user might choose this because it is also a D-sub style connector, but it has a different pin count, shape, and purpose.
- C. Incorrect.
Incorrect. RJ45 is used for twisted-pair Ethernet networking, not for a direct RS-232 serial connection from a DB9 UPS cable. This distractor reflects the common misconception that any management or communication cable can attach to a network port.
- D. Incorrect.
Incorrect. USB Type-B is typically found on printers and some peripherals, not on legacy UPS serial cables with DB9 connectors. While some modern UPS units use USB, a DB9-ended cable indicates the need for a serial COM interface instead.