User's Manual

10/19/07 888-2687-001 4-9
WARNING: Disconnect primary power prior to servicing.
Section 4 Theory of Operation
Ranger ™ Mobile Series
4.3.6.2 Life Support Mode, Main Controller
The CPLD handles most of the inputs and outputs or I/O to the Main Controller. It also
allows the CPLD to be able to maintain the transmitter on the air in a limited protection
mode called “Life Support” in case the micro module fails. In this mode, the main
function of the CPLD is to monitor the primary transmitter control and status lines and
interface the front panel controls (ON/OFF, Raise/Lower, Remote Enable/Disable) to
the rest of the transmitter.
In Life Support Mode, there is also limited remote control input available from the
External I/O Board via J11 on the Main Controller, including:
• Remote ON and OFF
• Remote Raise and Lower
• External Interlock
4.3.6.3 Manual RF MUTE
The Main Controller has a toggle switch, S3 which can be used to mute the transmitter
RF output without shutting it off. This switch is primarily used for initial turn on and
troubleshooting but can be used for any purpose which requires the RF output to be
muted. When activated, the GUI will indicate an RF MUTE is present.
4.3.7 External I/O Board
The primary function of the External I/O Board is exactly as its name implies. It is the
interface between the internal transmitter control system and all external or peripheral
devices. Input/Output or I/O ports on the External I/O Board include:
a. System Control Bus connection to the Main Controller which includes the CAN
bus and parallel control lines.
b. External I/O Control Cable which connects to the Main Controller. This cable has
an RS-232 connection and several discrete remote control and status lines which
will be used in the event of a failure of the CAN bus. These remote control and
status lines include:
1. On and OFF
2. Raise and Lower
3. External Interlock