Digi 90031300 manual Appendix E Generic T1 Modem Bank Wiring Modes, Eight-Wire Direct Wiring

Appendix E — Generic T1 Modem Bank Wiring Modes

There are three basic wiring modes for connecting T1 Modem Bank units to an EPC/X host adapter or to each other: Eight-Wire Direct, Four-Wire Direct (also called Four-Wire Self-Clocking), and Eight-Wire Synchronous Modem (or Eight-Wire Externally Clocked).

Eight-Wire Direct Wiring

Eight-Wire Direct is the standard method for connecting T1 Modem Bank units to EPC/X host adapter synchronous lines and to other T1 Modem Bank units. It provides transmit and receive data signals plus discrete clock signals for transmit and receive data. This permits synchronous data rates of up to 10M bps, which results in the maximum data throughput under moderate to heavy loads. (See Table 8 on page 96 for restrictions on cable lengths). The synchronous cables provided with the T1 Modem Bank units are Eight-Wire Direct cables. The Eight-Wire Direct cable is a twisted pair cable with a male HD-15 (high-density DB-15) connector at one end and a female HD-15 at the other end. The cable should be shielded, and the shield must be connected to the HD-15 connector shell at both ends. See Figure 33.

Figure 33 Eight-Wire Direct Daisy Chain Cable Wiring

94 T1 Modem Bank