Diagnostics - General DataComm 551 Operating And Installation Instructions

INTRODUCTION

DIAGNOSTICS

1-2
• The DataComm 551 detects both network- and customer equipment-gen-
erated errors and alarms, stores the number of occurrences of each,
and transmits the appropriate alarms to both ends.
• The DataComm 551 transmits a keep alive signal to the network when
it detects a loss of signal from the customer equipment side.
• The DataComm 551 can perform a variety of loopbacks and other tests.
• The DataComm 551 can provide power to the T1 span (in DataComm
FourPak, GDC TriPak, and Universal System Shelf installations, us-
ing a Telco-provided current source)
• The DataComm 551 can can be configured as a slave CSU, limiting the
configuration changes and diagnostics available via the Supervisory
terminal. This prevents actions which could disrupt service.
The DataComm 551 can be mounted in the following housings:
• Standalone single-slot DataComm Enclosure (model DE-7)
• Standalone four-slot DataComm FourPak Enclosure (model DFP-11)
• Rack-mountable sixteen-slot DataComm Modem Shelf (models DS-1,
DS-5R, and DS-5NR)
• Rack-mountable three-slot GDC TriPak Shelf (models TPS-1 and TPS-
2)
• Rack-mountable four-slot Universal System Shelf backplane (models
USS-1D, USS-1-DC/R, and USS-1-DC/NR)
(All rack-mountable housings fit into 19- and 23-inch wide equipment
racks.)
Table 1-1 shows which related products can be installed with the
DataComm 551 in these housings.
The DataComm 551 offers the following link-level (DS1) diagnostics:
• Alarm counts display
• ANSI Payload Loopback (PLB)
• AT&T DTE Loopback (DLB)
• AT&T TABS Maintenance Message Protocol support
• Bellcore Performance Report Messages support
• DS1 End-to-End Self-Test
• DS1 Line Loop