User's Manual

1.3.2 Detailed Theory of Operation
1.3.2.1 Low Power Backplane CCA Block Diagram Theory
Refer to Figure 1-5. The Low Power Backplane CCA provides interconnection and configuration for a
Model 2160/2170 DME System. The Low Power Backplane is an 84HP (approximately 16.8”) wide, 9 slot
card cage intended to fit in a standard 19” rack. The Low Power Backplane will accommodate both a single
or dual controlled/monitored DME system. It’s referred to as a Low Power Backplane because only low
power amplifiers may be inserted, while a high power DME or TACAN will have a separate, dedicated
High Power Backplane.
Configuration of the DME system resides on the Low Power Backplane CCA in the form of DIP switches.
Sixteen individual switches determine system configuration and eight switches set operating frequency.
System1 and System2 Low Power Amplifiers (LPA) connect to the backplane via J1 and J16 DB37
connectors with blind mate adapters (BMA). Each LPA also has an RF_OUT signal which eventually
connects to couplers for further processing.
The remaining circuit cards that insert into slots of the Low Power Backplane utilize both 96 pin and 60 pin
DIN41612 connectors. The 60 pin connectors have openings for RF connectors which carry RF signals to
and from the Monitor CCAs and RTC CCAs. For circuit cards such as the RMS and Facilities CCAs that
do no have RF signals, these RF connector positions are not populated.
System1 and System2 Receiver/Transmitter Controller (RTC) CCAs connect via J2/J3 and J14/J15 as well
as their RF connectors.
System1 and System2 Monitor / Interrogator CCAs connect to the backplane via J4/J5 and J12/J13 as well
as their RF connectors.
The RMS CCA connects to the backplane via J8/J9 and the Facilities CCA connects to the backplane via
J10/J11.
Connections between the Low Power Backplane CCA and a High Power Backplane CCA are accomplished
by 50 pin headers P5 and P6.
The J17 DB9 connector facilitates interface between the Low Power Backplane CCA and the Battery
Charge Power Supply (BCPS) modules for System1 and System2.
Power for the backplane enters via terminals E1 through E4 block TB1.
The LCU CCA is attached via 60 pin header P4.
The Interface CCA has two possible connections; the 60 pin header P1 for general purpose signals and the
40 pin header P1 if a TACAN antenna system must be controlled.
The Fan Control CCA is connected by 14 pin header P7.