CPP100
SECTION 7
CPP1OPS
25/10/06
www.snellwilcox.com
Version 1 Issue 6
7.1
Remote Control
PREFIX has provision to be remotely controlled via
the serial BNC network - S&W RollCall.
Interface to the "RollCall" communications network is
via the single BNC connector. Connections should be
made by means of a `T' piece (Zo=75 Ohms) to a 75
Ohm cable system as shown below. It should be
noted that both extremities of the cable system must
be terminated in 75 Ohms and the maximum number
of units limited to 25 on one single cable run.
The communications network is a specially designed
remote control network system and many more units
can be accommodated by using a "Network Bridge".
Remote control can come from either a dedicated
front panel or "shoe-box" or a standard IBM
compatible PC. Full protocol documentation and
more detailed information is available on request
from the supplier.
An RS 422 interface is available via the 9-pin female
D type connector. Further information about this port
is available on request.
Basic RollCall Operation
All the features from the menu system are available
remotely with the same options structure. This
maintains compatibility and facilitates easy operation
for users familiar with the unit.
The most common PREFIX remote configuration is
shown below where several compression pre-
processors are connected to the network for remote
control by one remote panel or "shoe-box".
Typical Set-up
The network address for each unit is set via the menu
system option "NETWORK". The default address is
20hex. When installing a network it is recommended
that a table similar to the one at the end of the
manual be kept up-to-date to allow fast and accurate
allocation of new unit addresses.
Parameter changes are reflected both locally and
remotely. For example, if the output is changed to a
test pattern by a remote unit then any further access
from the card edge to the PATTERNS option will
indicate this change. Similarly, if the card edge
changes a parameter then this will be reflected on the
display panel of the remote unit.
For more detailed information about the operation of
the remote panel or PC software please consult their
relevant manuals.
