M805-00
T805-04 Backplane
10.11
Copyright TEL
30/09/96
The ACL-II RS-485 serial communications board interfaces between the System Control-
ler and the first backplane of each RS-485 Group to implement the Group structure (see
Figure 10.5).
Note that in Figure 10.4 there are multiple links between the System Controller and
backplanes. Each of these links is the connection between the System Controller and a
different Group. The links are made to the first backplane of that Group, while the com-
munications are distributed to other backplanes in that Group via the PL-1/PL-3 link.
The link is terminated in the last backplane of the Group.
Shorting links on the backplane will determine whether or not the RS-485 signals are
passed onto the next rack and will depend on whether the next rack is in the same 32
member Group of TSGM/LEM combinations. Note that the audio and control signals
are passed onto the next rack, regardless of whether or not it is in the same group. They
will not, however, be passed on if the next rack is the beginning of another network.
In multi-rack systems there can be either one or two TSGM cards per network. If there
is one TSGM, it must occupy port 1 of the first rack (rack-1) in its network. As stated
previously, it is recommended that a new communications Group is started for each
new network in the T805 system. In this case the first rack of the network will have PL-1
unconnected to the previous rack in the system, but will use PL-3 to link audio and con-
trol signals (including RS-485) to the next rack in the network.
Under no circumstances should TSGMs occupy any other position than port 1 of
the first rack in the network (if one TSGM is used) or ports 1 & 2 of the first rack
in the network (if there are two TSGMs for that network).
If 1 TSGM is used, port 2 may be configured for either an LEM, AIM or ARM.
Summary of Contents for T805
Page 16: ...4 2 ASP Card Operation M805 00 30 04 95 Copyright TEL ...
Page 44: ...7 18 Initial Programming Adjustment M805 00 30 09 96 Copyright TEL ...
Page 70: ...14 1 2 PCB Information M805 00 30 04 95 Copyright TEL ...
Page 89: ...Copyright TEL 30 09 96 M805 00 T805 Front Panel PCB Information 14 5 3 ...