
Chapter 4 - Diagnostics
4.1.4 DSU Back-to-Back Test
This test lets you connect two DSUs with a
1.Obtain a DSU
2.Plug the cable into each DSU’s Line jack.
3.On the “good” DSU, set DIP switch #3 to the down position.
4.Set one DSU to internal clocking and the other DSU to DDS clocking.
5.Send data from your DTE, it should be “looped back” to your DTE. If you have access to a Bit Error Rate Tester, this can be used in place of the DTE.
DTE | “Suspect” | “Good” DSU in | |
| DSU | Cable | Loopback Mode |
Figure 4-4. DSU Back-to-Back Test Diagram
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