Black Box LR1530A-EU-R3 - Manual (Page 91)

Servicing Information
85
V.11 / X.21 Link Pinouts
Contact
No.
X.21
Circuits
Ref.
Circuit
Name
Direction
To From
DCE DCE
1 Protective Ground NA
2 T (A) Transmitted Data (A) X
3 C (A) Control (A) X
4 R (A) Received Data (A) X
5 I (A) Indication (A) X
6 S (A) Signal Element Timing (A) X
7 ----------
8 Ground Signal Ground NA
9 T (B) Transmitted Data (B) X
10 C (B) Control (B) X
11 R (B) Received Data (B) X
12 I (B) Indication (B) X
13 S (B) Signal Element Timing (B) X
14 ----------
15 ----------
Figure C-9 V.11 / X.21 Link Pinouts
The connecting cable must be a shielded cable.
Circuits which are paired (contain an (A) and (B) reference)
should be connected to twisted pairs within the connecting cable.
NOTE For U.K. Approval:
The connecting cable may be any length between 0 and 5M.