A number of different standards defines the signaling over a serial cable (including EIA/TIA-232, X.21, V.35, EIA/TIA-449, EIA-530, and HSSI). Each standard defines the signals on the cable and specifies the connector at the end of the cable. The documentation for the device being connected should indicate the signaling standard used for that device. If you cannot find the information in the documentation, use the illustrations below to select the signaling standard required. Select the connector that will mate with the connector on your device, rather than the illustration that looks like the connector on the device.