Toshiba CTX28 manual CSU Installation, Loop Back Testing, Rdtu Self Test

T1

CSU Installation

CSU Installation

Install the CSUs and wire them to the RDTU and NIU or customer premises T1 circuit, as required (see Figure 8-9).

Note Before connecting the CSU to the Telco line, notify the T1 provider. You should also notify the T1 provider before disconnecting the CSU.

CTX RDTU

Transmit

Receive

Local Loop Back

CSU NIU

Receive

Transmit

Network Loop Back

Network

T1

5801

Figure 8-9 CSU Local and Network Loop Back Tests

Loop Back Testing

The RDTU provides three loop back test configurations. These loop back tests should be performed as required in conjunction with CSU loop back tests (see CSU loop back test documentation).

RDTU Self Test

This test should be performed upon initial installation of a RDTU PCB. Program the RDTU per the Strata CTX Programming Manual; then perform the RDTU loop back test, per the instructions in Figure 8-10, before connecting the far end (CSU, Network, or CPE) T1 span line.

RDTU Self Check

RDTU3 (DS2155)

RDTU1/2 (MM8976B)

P1

P2

T1 Framer IC Chip

Remove NDTU Cable

CSU

Network

Interface

Unit

Network

6688

Notes

●RDTU1 & 2, move P1 and P2 to On (see Figure 8-7); RDTU3 move SW8 & SW9 to On.

●Remove NDTU cable from RDTU amphenol connector.

●After about 12 seconds, all RDTU LEDs (except PRI/SEC SYNC) turn Off.

●Appropriate Primary or Secondary sync. LED flashes if RDTU is Primary or Secondary reference.

●If RDTU is not a Primary or Secondary reference, then the Primary and Secondary sync LEDs should turn Off.

●Do not use the RDTU3A as a clock extraction unit.

Figure 8-10 RDTU Self Test

Strata CTX I&M 06/04 8-19