Specifications

2240 Fiber Optic Modem

4.6.1.1 RS-449 / DC-37 Interface

This interface complies with EIA Standard RS-449. Electrical characteristics comply

with RS-422 for clock and data signals and RS-423 for control signals. The interface

uses the physical connector type and pinouts specified in RS-449 (refer to Table 4-

H). The RS-449 / 422 interface uses a 37-pin, female D-Type connector for the

physical connection.

Table 4-H.

RS-449 Pinouts

for Model MC1

Pin RS-449 Direction

Number Pin Name

A/B (abbrev) (full name)

1 SHLD shield -

4/22 SD send data to modem

5/23 ST send timing from modem

6/24 RD receive data from modem

7/25 RS request to send to modem

8/26 RT receive timing from modem

9/27 CS clear to send from modem

10 LL local loopback to modem

11/29 DM data mode from modem

12/30 TR terminal ready to modem

13/31 RR receiver ready from modem

14 RL remote loopback to modem

15 IC incoming call from modem

17/35 TT terminal timing to modem

18 TM test mode from modem

19 SG signal ground -

20 RC receive common -

37 SC send common to modem

2/36 N/A extra clock for to modem

receive data