Timing-Control Module Supports 14 Input Signals

The Model STS100 module offers up a Synchronous Equipment Timing Source function in a Sonet/synchronous digital hierarchy (SDH) network element. The unit accommodates 14 individual input clock signals (low-voltage differential signaling, PECL, TTL) at N × 8 kHz multiples up to 155.52 MHz. It can generate 11 different outputs. Master/slave configuration for the synchronization of multiple timing cards is supported. The module provides Free Run, Locked, and Holdover modes of operation. The unit incorporates a connector interface, configurable bandwidths, and an autonomous "hitless" switchover function on loss of input. It also includes alarms for LOR and LOL. Supporting a microprocessor interface in serial or parallel, the module meets Telcordia GR-1244-CORE and GR-253-CORE specifications. The STS100 targets Stratum 3 and 4E Sonet or SDH Equipment Clock (SEC) applications. In 1000-unit lots, the modules cost $275 each.