The PA-4T+ provides the following electrical interfaces: EIA/TIA-232, EIA/TIA-449, EIA-530. X.21 and V.35. Each interface complies with its specific interface specifications. The cable attached to each PA-4T+ port adapter's interface ports determines its type (EIA/TIA-232 and so forth) and its mode (data communications equipment [DCE] or data terminal equipment [DTE]). Each interface allows a maximum bandwidth of 2.048 Mbps; the speed depends on the type of electrical interface used. Use EIA/TIA-232 for speeds of 64 kilobits per second (kbps) and below, and use X.21, EIA/TIA-449, V.35, or EIA-530 for higher speeds. Serial signals can travel a limited distance at any given bit rate; generally, the slower the baud rate, the greater the distance. The PA-4T+ contains the enabled LED, standard on all port adapters, and one status LED for each port. After system initialization, the enabled LED goes on to indicate that the PA-4T+ has been enabled for operation.