Digital Communications Interfaces ________________________________________________________
RF-MCGARDPRO
Hubbell Power Systems, Inc.
–
RFL™
Products
July 1, 2022
©2022 Hubbell Incorporated
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T1/E1 framer. This loops the data back to the local terminal before the line interface to help
isolate communications problems.
Figure 7-31. Digital Comms Test – Framer Loopback
7.6.4 Digital Comms Test
– Payload Loopback
A payload loopback is like a remote loopback. Payload loopback is only available for T1/E1
interfaces. A payload loopback test directs the local receive data to the local transmit path at the
T1/E1 framer. This loops the data back to the remote terminal, through the local framer, to help
test the complete communications circuit and isolate communications problems.
Figure 7-32. Digital Comms Test – Payload Loopback