M40e X.21 and V.35 Cable Pinouts for EIA-530 PIC
The EIA-530 PIC accepts X.21 and V.35 cable connectors.
- A V.35 connection requires an DB-25 to V.35 cable and connects to a V.35 data terminal equipment (DTE) 34-pin Winchester type male cable (one per port). Table 1 describes the V.35 cable pinouts.
- An X.21 connection requires an DB-25 to X.21 cable and connects to a X.21 DTE DB-15 male cable. Table 2 describes the X.21 cable pinouts.
Figure 1: EIA-530 PIC

Table 1: DB-25 Connector to V.35 Connector Pinout for the M40e Router
DB-25 Pin | Signal | V.35 Pin | Description |
|---|---|---|---|
2 | TD | P | Transmit Data |
14 | TD | S | Transmit Data |
3 | RD | R | Receive Data |
16 | RD | T | Receive Data |
4 | RTS | C | Ready To Send |
5 | CTS | D | Clear To Send |
6 | DSR | E | Data Set Ready |
20 | DTR | H | Data Terminal Ready |
24 | XTC | U | DTE Transmit Clock |
11 | XTC | W | DTE Transmit Clock |
15 | TC | Y | Transmit Clock |
12 | TC | AA | Transmit Clock |
17 | RC | V | Receive Clock |
9 | RC | X | Receive Clock |
1 | FGND | A | Protective Ground |
7 | GND | B | Signal Ground |
8 | DCD | F | Data Carrier Detect |
Table 2: DB-25 Connector to DB-15 (X.21) Connector Pinout for the M40e Router
DB-25 Pin | Signal | DB-15 (X.21) Pin | Description |
|---|---|---|---|
1 | FGND | 1 | Protective Ground |
7 | GND | 8 | Signal Ground |
2 | T | 2 | Transmit Data |
14 | T | 9 | Transmit Data |
3 | R | 4 | Receive Data |
16 | R | 11 | Receive Data |
4 | C | 3 | Request To Send |
19 | C | 10 | Request To Send |
8 | I | 5 | Data Carrier Detect |
10 | I | 12 | Data Carrier Detect |
17 | S | 6 | Receive Clock |
9 | S | 13 | Receive Clock |
