User guide

100 RealCT Direct API Developer Guide
Chapter 4: E1 Networking
Configuring the E1 Environment
Configuring the E1 environment involves the following steps:
1. Set the clock.
2. Load the line protocol.
3. Configure the carrier.
Setting the Clock
T1 and E1 boards must have their clock synchronized with the
network and with other boards connected in a CT bus. In a
CT bus, one board drives the clock and all other boards retrieve
the clock from the bus. If the system contains T1 or E1 boards,
the first such board drives the clock based on the signal it
receives from its network trunk A or B. This synchronizes the
CT bus with the T1 or E1 network. Otherwise, a RealBLOCS,
RTNI-ATSI, or Vantage PCI board uses its internal oscillator to
set the CT bus clock.
Configure the clock using CONFIG_CLOCK or using the
Configuration Wizard. For specific information about setting
the clock for boards in an CT bus, examples of system
configurations, and sample code see Configuring the MVIP-90
Clock on page 150.
If you do not set the clock correctly or if you specify more than
one board to drive the clock, you could either lose data or
transfer data improperly to other boards in the CT bus. An
incorrect clock setting can also lead to crackling on the line.