Metrodata FM4900, Руководство пользователя

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TEST & TROUBLESHOOTING
51 76-02-011F
9 TEST & TROUBLESHOOTING
Several diagnostic tests are supported by the FM4900. The fact that the E3 signal is framed
is used to identify a faulty or failed connection. In addition loop-backs may be activated to
segment the link, and test patterns may be generated or monitored to validate signal flow
along the path of the link.
Four types of test loops are available:
DTE Loop
DTE External Loop
NI Remote Loop
NI Local Loop
Diagrams showing the functioning of these test loops are given in this Section.
9. 1 Testing Menu
When you select the TESTING option from the MAIN SET-UP menu, the TESTING menu is
displayed.
Figure 9. 1 Testing menu
The interface to be tested and the type of test to carry out are selected using this screen.
Definitions of the menu items are given below.
9 . 1. 1 DTE
When DTE is selected, you can toggle between LOOP, EXTERNAL LOOP, and NONE.
9 . 1. 2 NI
When NI is selected, you can toggle between LOCAL LOOP, REMOTE LOOP, and NONE.
9 . 1. 3 External loop control
This item is either ENABLED or DISABLED. Note that if EXTERNAL LOOP CONTROL is
DISABLED, the unit cannot be put into EXTERNAL LOOP by remote units. The default
setting is DISABLED.
When DISABLED, the remote loop code receiver in the DSU is inhibited, so the FM4900 will
not accept remote loop commands from other DSU’s on the network. The HSSI control lines
LA and LB are also inhibited.
TESTING
DTE Loop
NI Local loop
Ext loop control Disabled
HIGHLIGHTED letter - select item
<escape> - exit menu