ServSwitch User's Manual

106
MATRIX SERVSWITCH™
Appendix E: Installing Modules in
the Matrix ServSwitch
E.1 Setting the RING/BUS Jumper (Jumper JP1) on Expansion Modules
Before you install Expansion Modules (our product code SW740C-R3-B) in a
daisychained Matrix ServSwitch system, you might need to set their RING/BUS
jumpers. If the daisychain is laid out in a bus topology (see Section 3.4.2), you
won’t need to set them—skip ahead to Section E.2. But if your daisychain is laid
out in a ring topology (see Section 3.4.2), you’ll need to set the RING/BUS
jumpers to the RING (off) setting on the Expansion Modules you’ll be installing in
any two adjacent Switches in the ring (units one and two, or two and three, or three
and four, etc.).
As shown in Figure E-1, the RING/BUS jumper (labeled “JP1”) is just behind the
DB15 IN and OUT connectors at the front of the Module. In the jumper’s original
shipped-from-the-factory state, it is set to BUS (the jumper covers both posts),
which is the appropriate setting for the bus topology. Set it to RING on the Modules
that will go in two adjacent Switches only by moving the jumper so that it covers just
one of the posts and leaves the other open. (You could just remove the jumper
entirely, but it’s a better idea to leave it “hanging” on one post so it can be easily set
back to BUS if your system topology changes.) Do not set this jumper to RING on
only one Switch, on more than two Switches, or on Switches that are not adjacent
(that is, not directly linked with an Expansion Cable).
Figure E-1. The RING/BUS jumper.
JP1