38 CHAPTER 1: INTRODUCTIONEach Analog Line Card contains the following lights and connectors:■ Status Lights (1 through 4) — Each light shows the status of theassociated line.Initialization:■ Fast steady blink — Waiting for software download.■ Solid on — Software has been downloaded. The flash memory onthe board is being loaded.■ Slow, non symmetric blinking pattern — Waiting for thecompletion of the binding process to the NCP.Operation:■ Off for 9 to 10 seconds, on briefly — Idle, the line is not in use.■ On for 9 to 10 seconds, off briefly — A telephone call isconnected on this port.■ Console Connector — This DB-9 connector provides an RS-232(DCE) TTY terminal connection for maintenance access.T1 Digital Line Card The optional T1 Digital Line Card lets you connect a T1 line to the NBXsystem. When configured as standard T1 (DS1), the T1 card supportsin-band signaling of 24 DS0 (64 Kbps) “voice” channels and a variety ofsignaling types and protocols. The T1 carries data at a rate of 1.544Mbps. When configured as ISDN PRI, the T1 card supports 23 voicechannels with PRI services such as Direct Inward Dialing (DID).You must have an external Channel Service Unit (CSU) when you use the3C10116C T1 Digital Line Card. 3C10116D includes an onboard CSU.The 3C10116D can provide CSU performance statistics, supportsloopback testing, and can be configured as a remote device thatcommunicates with its NCP over a routed network.CAUTION: 3C10165D E1 Digital Line Cards and 3C10116D T1 DigitalLine Cards can have their flash memory corrupted if you remove powerfrom the cards or remove the cards from the NBX chassis while they arereceiving their download after a system upgrade.ISDN PRI services require specific circuit provisioning, which you mustobtain before you can use the T1 card in PRI mode. See Appendix B formore information.
