Nortel 2750, Руководство по установке

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Appendix A Technical specifications
NN46110-318 02.01
3. At each end, the cable shield and connector shell must connect respectively to pin A of the 34-pin connector and
pin 1 of the standard 28-pin connector.
4. Do not connect Shield to Signal Ground because these are separate signals.
Table 34 provides the X.21 cable pinouts. (The pair suffix A or B refers to an
individual wire within a twisted pair.)
Table 34
X.21 cable pinouts
Standard-wired
end 28-pin male Signal name
Pair number
and conductor
Standard-wired
end 15-pin male Notes
2 TXDA pair 1A 2
14 TXDB pair 1B 9
3 RXDA pair 2A 4
16 RXDB pair 2B 11
15 TXCA pair 3A 6
12 TXCB pair 3B 13
17 RXCA pair 4A pair 5A Note 1
9 RXCB pair 4B pair 5B Note 1
24 SCTEA pair 5A pair 4A Note 1
11 SCTEB pair 5B pair 4B Note 1
4 RTSA pair 6A 3
19 RTSB pair 6B 10
5 CTSA pair 7A 5
13 CTSB pair 7B 12
6 DSRA pair 8A no conn Note 2
22 DSRB pair 8B no conn Note 2
20 DTRA pair 9A no conn Note 2
23 DTRB pair 9B no conn Note 2
8 DCDA pair 10A no conn Note 2
10 DCDB pair 10B no conn Note 2
18 LL pair 11A no conn Note 2
21 RL pair 11B no conn Note 2
25 TM pair 12A no conn Note 2
26 M0 pair 12B no conn Note 2
27 M1 pair 13A no conn Note 2