Filter
Top Products
B-4
Cisco Wide Area Virtualization Engine 594 and 694 Hardware Installation Guide
OL-24619-02
Appendix B Maintaining the WAVE-594 and WAVE-694
Maintaining Your Site Environment
Electromagnetic and Radio Frequency Interference
Electromagnetic interference (EMI) and radio frequency interference (RFI) from a system can adversely
affect devices such as radio and television (TV) receivers operating near the system. Radio frequencies
emanating from a system can also interfere with cordless and low-power telephones. Conversely, RFI
from high-power telephones can cause spurious characters to appear on the system’s monitor screen.
RFI is defined as any EMI with a frequency above 10 kilohertz (kHz). This type of interference can travel
from the system to other devices through the power cable and power source or through the air like
transmitted radio waves. The Federal Communications Commission (FCC) publishes specific
regulations to limit the amount of EMI and RFI emitted by computing equipment. Each system meets
these FCC regulations.
To reduce the possibility of EMI and RFI, follow these guidelines:
• Operate the system only with the system cover installed.
• Ensure that the screws on all peripheral cable connectors are securely fastened to their
corresponding connectors on the back of the system.
• Always use shielded cables with metal connector shells for attaching peripherals to the system.
Magnetism
Because they store data magnetically, hard disk drives are extremely susceptible to the effects of
magnetism. Hard disk drives should never be stored near magnetic sources such as the following:
• Monitors
• TV sets
• Printers
• Telephones with real bells
• Fluorescent lights
Shock and Vibration
Excessive shock can damage the function, external appearance, and physical structure of a system. Each
system has been designed to operate properly even after withstanding a minimum of six consecutively
executed shock pulses in the positive and negative x, y, and z axes (one pulse on each side of the system).
Each shock pulse can measure up to 5 gravities (G) for up to 11 milliseconds (ms). In storage, the system
can withstand shock pulses of 20 G for 11 ms.
Excessive vibration can cause the same problems as mentioned earlier for shock, as well as causing
components to become loose in their sockets or connectors. Systems can be subject to significant
vibration when being transported by a vehicle or when operated in an environment with machinery that
causes vibration.