ADTRAN DSU 56 user manual Near END Tests, DTE only Test

Chapter 3. Test Modes

If an EPROM CHECKSUM failure is detected during self test, CS, ALM, PTRN, and ERROR indicators all flash at the end of the self test.

NEAR END TESTS

The local DSU 56/64 can perform the following near end tests:

•DTE Only

•DTE with Test Pattern

•DTE and LOOP (LL)

•Loop Only (RT)

DTE ONLY TEST

The DTE ONLY test can test both the DTE interface of the local DSU 56/64 plus its loop transmitter and receiver. For this test, the loop transmit data is connected to the loop receive data at a point close to the physical network interface.

The loopback point and the signal paths for this test are shown in Figure 3-1.

DTE or Test Equipment Interface

TD

RD

	56/64 DSU	Network
DTE	Loop	Interface
Transmit	Transmit
Interface	Interface
		Loop TX
	DTE
	Only
		Loop RX
DTE	Loop
Receive	Receive
Interface	Interface

Figure 3-1. DTE Only Test Diagram

3-2 DSU 56/64 User Manual 61200062L1-1