ACC Installation and Configuration Guide

66 Chapter4
Dual Interface Configurations
Introduction
Introduction
ThedualMUXinterconnectpanelsorcablesaredesignedtoallowtwo
ACC ca rds to b e connected to a single network port. The interconnect
panel is typical used to connect two ACC cards installed in two separate
HP 9000 systems, but the panel can also connect two cards in the same
system. (This may be useful for prototyping and test situations.)
Each output port on the dual M UX interconnect panel or cable may be
controlled by either ACC MUX card, but care must be taken that both
MUX cards don’t attempt to access or control the s ame port at the same
time. One MUX card must have the port configured as being in
“loopback” mode (tri-state), and the other must have the port configured
as being in “RS232”, “X21”, or whatever mode is appropriate.
In order for a port to be handed off from one card to the other, the port
being controlled must be put into “Loopback” mode from the card that is
currently controlling it. The port can then be placed into the appropriate
mode (such as RS232 or X21) by the other card, which can then begin
controlling it.
The following sections describe how the control of MUX ports may be
shared between the two cards or handed off from one card to the other.
•AffectingPortMode
•DefaultPortModes
• Checking Port Modes