StarTech.com 6ft (1.8m) 2-Port FTDI USB to Serial RS232 Adapter Cable with COM Retention, USB to RS232 Adapter - TAA

CAB-SS-V35FC=

CAB-SS-V35MT=

CBA-R31-C09ZAR

A920-CONS-KIT-S=

CBA-RF2-C09ZAR

HOW SURGE EVENTS HAPPEN
In a normal equipment environment there are reasonable threats from Electrostatic Discharge (ESD) and lightning transients which can cause loss of data integrity and permanent damage to equipment if not controlled.
ESD threats are generated by personnel movement, which causes triboelectric (rubbing causing a separation of charge) charges to accumulate on equipment or clothing and then be discharged through hand or tool "touch". This discharge can represent several thousand volts at 10 to 30 amps of current. There are two primary threats from an ESD event. These are the peak current of the discharge and the resulting electromagnetic field. Should the input to the device not be protected from this ESD threat, as little as 100 milli-Joules can cause permanent failure to an input device at the silicon die level.
Lightning also can create a large disturbance and delivery destructive energy to the equipment. These lightning events cause differential voltages to develop as a result of inductance in the protective earth ground path to the equipment. During a direct lightning strike it is possible to measure peak currents into the Kilo Amp range. These events can occur both at the facility as well as outside the facility along utility power lines. When they occur on the power line outside of the facility peak currents can be extended in time due to the additional inductance of the power line. A normal event may be 10 usec zero to peak, with a decay of 200 usec. These currents are called longitudinal. The Cisco surge protection cable will adequately prevent this transient damage from occurring to within the industry standards for lightning protection devices. A good equipment chassis protective ground is strongly recommended to assure adequate protection.
EFT disturbances occur as a result of arcing contacts in electro-mechanical switches and relays commonly found in an industrial environment. The electro-mechanical switches are used to connect and disconnect inductive loads. Like ESD, EFT can be especially fatal on data and I/O lines. The fast rise time of the EFT pulses demand similar protection as ESD pulses.

CONFIGURATIONS THAT ARE SUBJECT TO SURGE EVENTS
There are several hardware configurations and applications that are more subject to damage from ESD events. These configurations include the following:
- Locations Subject to Electrical Storms-Any location where electrical storms are common is a good candidate site for surge protection on the serial ports;
- Unshielded Cables-If unshielded cables are used to connect to the serial port, it is much more likely that electrical discharges will be picked up by the cabling and damage the serial port;
- Long Cable Runs-The longer the cable, the more susceptible it is to surge events, even if the cable is shielded;
- Outside Wiring-If the cable runs outdoors, it is more susceptible to surge events;
- Different Earth Grounds-If the router and the device at the other end of the serial cable are connected to different earth grounds, then the cable can become a conduit for current that equalizes different ground potentials;
- Installations with Multiple Serial Port Failures-If an installation has experienced multiple serial port failures in the past, it is a good candidate for surge protection;

There are two types of devices that can communicate over a serial interface: DCE and DTE. A DCE provides a physical connection to a network and forwards traffic. A DTE connects to a network through a DCE device. Typically, a DTE device is connected to a DCE device (or vice versa) rather than another DTE device. Check the documentation that ships with your serial device to determine if it is a DTE or DCE device. If you cannot find the information in the serial device documentation. This table summarizes serial devices that can be connected to the router serial port and whether the device is considered a DTE or DCE device. The Cisco 805 router is a DTE device by default.

Cable - RS232: 9 ft. (2.8m) coiled, NCR 7448

No

CABLE RS232 FEMALE CONNECTOR 2.8M COILED POWER PIN 9 -30C

Smart Serial WIC2/T 26 Pin -V.35 Female DCE

SS-V35MT - Cable DTE 3m , for Cisco routers 2600, 3600, 3700

RS232, 2.8m

Serial Console Kit, USB-to-RJ45 cable, Spare

RS232/DB9 Female Connector, 2.8m Coiled, Power Pin 9, -30C

Cisco

Cisco

Zebra

Cisco

Zebra