Comtech EF Data SMS-7000, Installation And Operation Manual

Page: 105 / 148

Rev. 3 4–1
4
Chapter 4.
THEORY OF OPERATION
This chapter provides the theory of operation for the switch and explains various
interfaces and switching modes.
4.1 Interfaces
4.1.1 Configuration
The configuration interfaces (J1 and J2) are located on the rear panel of the SCU (refer
to Figure 4-1).
•
User remote (J1) is the remote port for configuration and control of the switch
and associated modems. From the SCU front panel utilities menu (refer to
Chapter 3), J1 is defined as EIA-232 or EIA-485 at 110 to 19200 baud rate.
•
Modem remote (J2) is the port through which the switch controls and monitors
modem configurations.
The J1 and J2 serial ports are electrically isolated but share the same address space. The
switch buffers communicate between the two ports. This enables a remote user to
communicate directly with the switch or modems attached to the switch, as though the
ports were directly connected.
If the switch is communicating with a modem at the time the remote user issues a
command, the switch responds with “BUSY.”