Chapter 2. Installation
DCE Connector
The connector labeled DCE provides connection to an external DSU/CSU. The pinouts for this connector are shown in the appendix Pinouts.
The connection between the FSU and an external DSU is a direct connection. When connecting to an external DSU, the FSU emulates an externally timed DTE interface connected directly to the DCE interface of the external device.
DTE Connectors
DTE devices are connected to the DTE connectors using either an RS-232 DTE cable or a CCITT V.35 DTE adapter cable. The maximum cable lengths recommended are 50 feet for the RS-232 and 100 feet for the CCITT V.35. The pin assignments are listed in the appendix Pinouts.
The V.35 adapter cable is recommended for use with data rates above 19.2 kbps. A low capacitance RS-232 cable works up to 56 kbps. The DTE ports are configured through the front panel or the VT 100 control port. The DTE ports can operate in asynchro- nous or synchronous modes.
Main Telco Connector
The Main connector is an eight-position modular jack which provides connection to the dedicated (DDS) network. See the appendix Pinouts for the Main connector's pin assignments.
Backup Connector
The eight-position modular jack labeled BACKUP is provided to allow future enhancements to the FSU (dial backup options). With the dial backup option installed, this connector will pro- vide connection to the switched telco circuit.
8 | FSU User Manual | 61200.130L1-1 |
