5. X.21 bis V.36 bit tim ing ca ble - (37 way to 37 way D type plugs).
CCITT cir cuit Tim ing Source (DCE)
Tim ing Sink
(DTE)
CCITT cir cuit
103-A 4 6 104-A
103-B 22 24 104-B
104-A 6 4 103-A
104-B 24 22 103-B
105-A 7 13 109-A
105-B 25 31 109-B
109-A 13 7 105-A
109-B 31 25 105-B
115-A 8 17 113-A
115-B 26 35 113-B
102-A 19 19 102-A
102-B 20 20 102-B
* In some cases it may be nec es sary to con nect this line to GND (102) at the re ceiver end of th e link
de pend ant upon the im ple men ta tion of the in ter face con trol lines - bal anced or un bal anc ed.
6. RS530 bit tim ing ca ble (25 way to 25 way D type plugs).
CCITT cir cuit Tim ing Source (DCE) Tim ing Sink (DTE) CCITT cir cuit
103-A 2 3 104-A
103-B 14 16 104-B
104-A 3 2 103-A
104-B 16 14 103-B
105-A 4 8 109-A
105-B 19* 10* 109-B
109-A 8 4 105-A
109-B 10* 19* 105-B
115-A 17 24 113-A
115-B 9 11 113-B
102 7 7 102
* In some cases it may be nec es sary to con nect this line to GND (102) at the re ceiver end of th e link
de pend ant upon the im ple men ta tion of the in ter face con trol lines - bal anced or un bal anc ed.
A-12
a telecom User Guide High Speed Mo dems
