DEMULTIPLEXER CHANNEL ELECTRONICS SETUP PROCEDURES-CONT.

T.O. 31W2-2GSC24-2

TM 11-5805-688-14-1

NAVELEX 0967-LP-545-3010

includes the 48-kbps channel rate desired.

(Rp) shown on sheet 4 of the worksheets. Multiply K

and Rp, and compare this value (KRp) with the channel's

10. Note the rate range (A, B, C, or D) selected

output data rate (Rc).

in step 9 and set S7 to the corresponding position. For

16. If Rc is equal to KRp (Rc = KRp), set S3 to the

example, if range B was selected, S7 would be set to the

SB position, which completes the SB card setup process.

B, C, D position. If range A was selected, 57 would be

set to the A position.

Install the SB card in its appropriate slot (1 through 15) in

the DEMULTIPLEXER row. If Rc is less than KRp (Rc <

11. Set S8 to the rate range selected in step 9.

KRp), set S3 to the URD position and perform steps 17

through 19.

12. Set S24 to the rate range selected in step 9.

NOTE

13. Set S25 to the rate range selected in step 9.

In cases where Rc < KRp, coarse rate

NOTE

conversion of KRp to Rc must be

Certain positions of S12 indicate rate

performed by the demultiplexer. To

ranges A' (A prime) and B' (B prime).

enable this conversion, a fill bit value

When S5 is set to the A range and the

must be computed and set into the

channel rate (Rc) listed on the

SB by 10-position switch S2.

worksheet is 1.5 Mbs or greater, S12

must be set to the A' position. For

17. Determine the quantity of fill bits required,

using the expression:

channel rates in the A range which

are below 1.5 Mbs, and for any

Fill bits = 899K (1 - Rc )

channel rate in the B range, the A'

KRp

and B' positions of S12 are used in

where

cases

where

the

multiplexer's

K = quantity of ports assigned to the channel (from

channel output smoothing interval is

worksheet)

unacceptable

user

sink

instruments. In such cases, special

Rc = channel data rate (from worksheet)

instructions will be added to the

configuration

worksheets.

Rp = port rate (from worksheet).

Discussion pertaining to selection

and use of S12 A' and B' ranges is

NOTE

contained in paragraph 3-58.

To ensure a proper computation of fill

14. Set S12 to the rate range selected in step 9

bit quantity, the value of 1 - Rc/KRp

or as instructed in the above note.

must be determined to seven decimal

places. Overall fill bit quantity, when

15. Refer to sheet 3 of the worksheets, and note

computed, must be rounded to the

in the PORTS K blocks the number of ports (K) assigned

nearest whole number; i.e., 316.7 is

each

channel.

Note

the

port

rate

rounded to 317, etc. The largest

number of

Change 2 3-47