Redundant Tracking Backup; Features; Hardware - ETC sensor+ CEM+ Manual

Appendix C

Redundant Tracking Backup

Features

In European ESR racks, Redundant Tracking Backup (RTB) systems feature two control modules per
rack with the ability to switch between the control modules automatically upon detection of errors,
failure or manually. The manual switching can be done from the front of the rack or from a remote
contact closure wired into the rack.
This is not available for any other Sensor+ rack types other than ESR racks.
The doubling of control modules in a rack means that the maximum number or racks in a group is
limited to 8. The maximum total number of CEM+s in a group is always 16.

Hardware

In order to fit two control modules to the rack, a special dual backplane is required. If you require an
upgrade to a dual backplane, contact ETC. See
There is a three position switch provided to the left of the control modules that allows control to be
switched to either the top or bottom control module. When the switch is in the centre position control
is automatically given to the module with the least errors, or the top module if there are no errors.
When the switch is in the upper or lower position control is given to the upper or lower CEM+.
There is a option for remote switching between the top and bottom module of each rack, provided by
the four pin J12 connector on the rear of the dual backplane. This can be wired to remote switching
and remote status indicators as shown below.
+12Vdc
Header at the top of
the backplane PCB
The +12 VDCsupply can either be from the internal rack power supply provided at the backplane, or an
external 12 VDC power supply.
Redundant Tracking Backup
An indicator lamp
50 mA 12 VDC max for
internal power supply
COM
Help from ETC Technical Services
Position B - Secondary
Position A - Primary
page 2
on .
J12
1 2 3 4
Orange remote tracking header.
Pin 1 is the pin closest to the
phase bars (left side of the rack
as you look in)
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