Product Manual - DM991 Series V Family - 204.4092.08
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13.
CONVERTER MODE TESTS
The Converter Mode is only available on equipments DM991S and DM991C.
Tests can be activated by the terminal/management, by CT141, or even by keys (only in DM991S).
Remember that signal CT141 must be set up as controlled in the digital interface, so that testing can be
enabled.
13.1. Local Analogue Loopback - LAL
Pressing the LAL (DM991S) key, activating this test through the Telebrás management or when CT141
turns ON, (if controlled) the equipment goes into local analogue loopback test.
In this test, the transmission data are returned to the reception. The loopback is done inside the G.703
interface, passing through the complete converter analogue circuit, as seen Figure 30.
The test signal can be given by DTE or by the converser.
If the equipment is working with a regenerated clock, activating the test, the clock will automatically be
altered to an internal clock. The led test and the led 109 will light up. When using the digital interface,
signals CT142 and CT109 are set to ON. On the TX-OUT line the signal is transmitted normally, meaning
the same signal returning to the digital interface.
The converter will remain in the test conditions until the key or CT141 is deactivated, or until the test is
stopped by Telebrás management.
Figure 30.
LAL test Converter Mode
13.2. Local Digital Loopback Test - LDL
Pressing the LDL (DM991S) key or activating this test by management forces the equipment to run the
local digital loopback test.
When the digital interface is being used the DTE transmission data (CT103) are redirected to the DTE
reception (CT104). The loopback is done inside the V.35 - V.36/V.11 converter interface. Simultaneously
the signal recovered in the G.703 interface line IN is again retransmitted to line OUT, that is, the loopback
is also done between the G.703 interface receive and transmit drivers. The test led, the 109 led, the
CT142 and the CT109 are set as ON. In this way this test verifies the connection and the interface with
the local DTE, as well as the connection with the remote side.
The converser will remain in the test conditions until the key is deactivated, or until the test is stopped by
the management. If the test is activated by the key and disabled by the management the key will remain
pressed but the equipment will leave test mode. This can be detected by the TEST LED on the front
panel. In case the configuration is altered after that, the equipment will go into test again, once it will
recognize once more the key
Summary of Contents for DM991C
Page 1: ...DM991 SERIES V DM991C DM991CE DM991S DM991SE PRODUCT MANUAL 204 4092 08 rev 08 Date 8 12 2008 ...
Page 66: ...Product Manual DM991 Series V Family 204 4092 08 66 Figure 31 LDL Test Converter Mode ...
Page 89: ...Phone 55 51 3358 0100 Support 55 51 3358 0122 Fax 55 51 3358 0101 www datacom ind br ...
