Both passive and active copper cable assemblies are available.The passive cable assembly design has no signal amplification in the cable assembly. Electronic Dispersion Compensation (EDC) is typically used on host board designs when passive SFP+ Cables copper assemblies are utilized. EDC allows for an extended length of passive cable assemblies. The industry standard EEPROM signature enables the host system to differentiate between a passive copper cable and a fiber optic module.The active cable assembly design has signal amplification and equalization in the assembly. Active copper assemblies are typically used in host systems that do not employ EDC. Active SFP+ Cables assemblies also incorporate Rx LOS and Tx Disable features. As with passive cables, the industry standard EEPROM signature enables the host system to differentiate between an active copper cable and a fiber optic module.
This should be done carefully to ensure the cables are firmly in place and will not move, but not so tight as to deform or stress the cable jacketing. SFP+ Cables come in 1-meter (3.3 ft) increments. Often installers will standardize on a small number of standard lengths to simplify the bill of material. One cannot always anticipate possible infrastructure obstacles on site so it is good practice to estimate long when QSFP-H40G-CU1M – Compatible Cisco 40GbE QSFP+ QDR Direct-Attach Copper Cable 1m efining cable lengths. Therefore, it is possible that there will be cable slack and this needs to be managed properly to ensure reliable long term performance. The slack in the cable should be shaped and looped so as not to violate bend radius. Slack or loops should be securely tied in place so they do not slip or sag over time.