GatesAir Intraplex DS-64NC, Installation And Operation Manual

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2 – Functional Description DS-64NC Synchronous Data Module
Version 9.1
GatesAir 2-11
Intraplex Products
Notes: In an E1 (2 MB) multiplexer, Time slot 0 is always reserved for framing. In an E1 variable
rate multiplexer, the time slot may be used to carry payload.
In the E1 CAS signaling format, Time slot 16 is reserved for signaling and multi-frame
synchronization. If CCS signaling is used, time slot 16 is available for payload. Setting the CAS
switch on causes the multiplexer to skip time slot 16 when filling either sequential or
alternating time slots.
Using the previous example of a DS-64NC module set up to use seven time slots, if the CAS
switch is turned on, selecting sequential usage places data in slots 10, 11, 12, 13, 14, 15, and
17, while alternate usage occupies slots 10, 12, 14, 18, 20, 22, and 24.
2.7.3 Loopback Mode Selection
Switches S3, positions 1 and 2 are used to select the DS-64NC loopback mode. Table 2-6 shows the
available modes and their respective switch settings.
Table 2-6. Loopback Settings – S3, Positions 1 & 2
S3/1 Setting S3/2 Setting Description
UP UP No loopback; normal operation
UP DOWN Activates Local (payload) loopback (near end)
DOWN UP Activates equipment loopback
DOWN DOWN Activates remote loopback
2.7.4 Test Pattern Generator Setup
Switches S3, positions 3 - 5 select the activity of the test pattern generator built into the DS-64NC
module. Four modes are available:
●
No test
● All ones
● One one and 15 zeroes
● A 15-bit pseudo-random number generator (PRNG)
Also, when the module is operating in its “56K” mode, the eighth bit of each byte is set to one, and
these bits are monitored on the receive side for errors, whether the data is live or test. A module can
be set either to generate a test pattern or to verify receipt of a test pattern. However, when a
loopback is active and the module is set to generate a test pattern, it simultaneously verifies the same
pattern. Table 2-7 shows the switch settings for each of these modes.
Table 2-7. Test Pattern Settings – S3, Positions 3-5
S3/3 Setting S3/4 Setting S3/5 Setting Description
UP UP UP No test
UP UP DOWN Generate all ones*
UP DOWN UP Generate PRNG*
UP DOWN DOWN Generate 1:15 ones*
DOWN UP UP No test
DOWN UP DOWN Verify all ones
DOWN DOWN UP Verify PRNG
DOWN DOWN DOWN Verify 1:15 ones
* These test modes also verify the same pattern if any loopback is active at the same time.