ESI - Extended Reference Input
The ESI (External Synchronization Input) card is capable of adding additional synchronization sources to an IMS system. It accepts E1 and T1 sources, both as a Bitstream (2.048MBit/s/1.544Mbit/s, supporting SSM/BOC) or Frequency (2.048MHz/1.544MHz).It also handles a configurable frequency (1 kHz - 10 MHz) and a 1PPS pulse synchronization source, if required. An ESI card is, as the MRI card, dedicated to one specific clock module (depending on the slot it is installed in) and can be installed in both ESI as well as MRI slots.