Specifications

HS-RN MP-2100/2104 Ver. 12.6, MP-4100 Ver. 2.0 4-1
Chapter 4
Diagnostics and
Troubleshooting
This chapter explains the specific diagnostic functions of the HS-RN modules and
provides troubleshooting information.
For a description of the alarm and configuration (“sanity”) error messages
generated by HS-RN module, refer to
Appendix B of the Megaplex-2100/2104
Installation and Operation Manual
or Chapter 6 of the Megaplex-4100 Installation
and Operation Manual
.
The diagnostic information presented in this chapter supplements the general
diagnostics and troubleshooting information instructions contained in the
corresponding
Megaplex Installation and Operation Manual .
4.1 Test and Diagnostic Functions
The available test and diagnostics functions are:
• Local digital loopback on the desired module channel.
• Remote digital loopback on the desired module channel.
The following sections describe the available test activities.
Local Digital Loopback (Local Loop)
The local digital loopback is performed at the input of the digital circuits serving
the corresponding channel.
When the loopback is activated, the channel transmit signal is connected to the
input of the receive path, and is returned to the user's terminal equipment. The
transmit signal is still sent to the remote Megaplex.
The loopback signal path is shown in
Figure 4-1 .
Remote Digital Loopback (Remote Loop)
The remote digital loopback is performed at the receive output of the channel
receive path, by connecting the digital signal received from the main link to the
input of the channel digital transmit path.
When the loopback is activated, the digital receive signal remains connected to
the input of the receive path, and is returned toward the remote end.