5.0 Expansion Cards - Focal 907 User Manual

907-0601-00 Rev. C Model 907 Video/Data Multiplexer – User's Guide

5.0 Expansion Cards

Expansion cards are used to increase the number of serial data channels or to add different analog or digital
format capabilities to a multiplexer system. Expansion cards require a motherboard to provide power and the
optical link between the remote and console cards. Using an asynchronous over-sampling of serial data lines,
expansion cards can time division multiplex many low speed serial channels onto one high-speed serial
channel. Expansion cards send and receive their time division multiplexed data over the optical link via the
data port lines on the backplane PC/104 connector of a 907 motherboard.
Switch settings on each expansion card select which of the six backplane data port lines are used. The
standard 907 motherboard has six on-board data channels which are also connected to the six data port
lines. When one of the six data ports is assigned to a stacked expansion card, the corresponding onboard I/O
circuits on the motherboard are disabled to avoid a conflict. For example, if a 907-485 expansion card is
assigned to data port 5, then the channel 5 RS-485/422 channel on the 907 card itself is disabled while the
expansion card overrides it. Furthermore, the RS-232 channels (1-4) on the standard 907 card run on dual
transceivers, so disabling one channel always disables a second channel, i.e. channels 1/2 or channels 3/4.
Removal of an expansion card automatically re-enables the motherboard channel(s).
The 907V motherboard has no on-board data channels but still has six data port lines available on the PC/104
connector. So adding expansion cards does not disable anything on the 907V motherboard. Similarly, the
907Plus motherboard has six dedicated data channels locally plus six independent data port lines via the
PC/104 backplane data channels. This provides a total of twelve simultaneous data ports with no disabling of
channels required on the motherboard. The 907-HDM2 and 907-GEM multiplexer cards also support
expansion cards with six independent data port lines as with the 907Plus.
Four to six expansion cards may be stacked on a 907 motherboard, limited by the availability of data channels
on the motherboard and the collective current draw of all cards in the stack through the motherboard.
Caution: Some expansion cards allow access to only a subset of data port lines. Ensure configuration
drawings are checked for data port options prior to setting up a system. All expansion cards attached
to a single motherboard must be switch configured to access different data port lines or data will be
corrupted. The corresponding expansion cards at the other end of the system must be configured to
match the same parts. For example, if one remote stack includes a 907-EIBS expansion card on port 1
and a 907-232 expansion card on data port 2, the console stack must also be configured with a
907-EIBS on data port 1 and 907-232 on data port 2.
Focal Technologies Corp. Page 5-1