25-Pin To 15-Pin Straight Through Cable - External Clock - Digi TransPort User Manual

Signal
GND
CTLB
CLKB
CLKA
INDA
CTLA
Note that Frame Ground is optional.
X.21 25-Pin to 15-Pin straight through cable - external clock
This is normally the cable to use to connect an X.21 terminal (such as, an ATM) to the Digi. Use
this cable when the Digi is the clock sink or configured as external clock.
Signal
Frame Ground (Case)
RxDA
RxDB
TxDA
TxDB
INDB
GND
CTLB
CLKB
CLKA
INDA
CTLA
Note that Frame Ground is optional.
Note When operating an X.21 (RS-422) link synchronously, it is necessary to fit termination
resistors to each signal pair at the receiving end. The Digi unit has in-built terminating
resistors, but terminating resistors should be fitted between the RxDA and RxDB pins,
CLKA and CLKB pins and INDA and INDB pins at the DTE.
Digi TransPort User Guide
DB 25 - Digi Side
Pin # (DCE)
7
8
15
17
20
22
DB 25 - Digi Side
Pin # (DCE)
Shield
2
3
4
5
6
7
8
15
17
20
22
DB 15
Pin # (DTE) Signal
8 GND
10 CTLB
13 CLKB
6 CLKA
5 INDA
3 CTLA
DB 15
Pin # (DTE) Signal
Shield Frame Ground (Case)
4 RxDA
11 RxDB
2 TxDA
9 TxDB
12 INDB
8 GND
10 CTLB
13 CLKB
6 CLKA
5 INDA
3 CTLA
IR2140
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