Cables and Connectors
Serial host interface specifications
MAX 4000 Series Hardware Installation Guide
Preliminary November 4, 1998
C-21
For the Host/BRI module
Each ISDN BRI line provided by the Host/BRI module (MX-SL-8BRIT) must end in a 100
Ω
termination. The maximum cable distance between the Host/BRI and its termination is 3280
feet (1000 m). You can install the local ISDN BRI device anywhere along the length of the
cable. Use only cable specifically constructed for ISDN BRI S interfaces.
Serial host interface specifications
Specifications for the serial host ports on the MAX include cabling requirements, timing
requirements, and interface types.
The MAX unit’s serial host ports are compatible with the following three electrical standards:
•
RS-449/422
•
V.35
•
X.21
The MAX also supports the following dialing/answering protocols at any of its serial host
ports:
•
V.25 bis
•
RS-366
•
X.21
Selection of the proper cable between a serial host port and the serial device ensures:
•
The proper mapping of pinouts from the MAX to the application equipment
•
Proper voltage levels
In the cable wiring tables that follow, the MAX is the Data Circuit-Terminating Equipment
(DCE) device, while the host equipment is the Data Terminal Equipment (DTE) device. The
serial host interface cabling tables use the abbreviations listed in Table C-19. Note that the
MAX supplies the Send Timing and Receive Timing clocks to the host.
Table C-19. Serial host interface cabling abbreviations
Abbreviation
Explanation
FGND
Chassis Ground
SGND
Receive Common Ground
SD+
Send Data +
SD-
Send Data -
RD+
Receive Data +
RD-
Receive Data -
ST+
Send
