MXi005U OPERATIONS AND MAINTENANCE
Setting = not Installed for all MXi005U transmitters
E18
Direct Vswr Relay reset from the Remote Reset Command
This jumper allows the Remote Reset Command to directly clear the VSWR trip relay
Setting = Installed for all MXi005U transmitters
E19
Forward Power Detection Type
Setting = PK for all MXi005U transmitters
2.2
2.3
2.3.1
R
EMOTE
C
ONTROLS AND THE
MXi005U
F
RONT
P
ANEL
ON/OFF
B
UTTON
The Front Panel ON/OFF button on the MXi transmitter can function in two distinct modes which depends on the
position of jumper E5 on the 31C1897 control board located inside the MXi transmitter chassis. E5 that can be
placed in either of two positions, one labeled ‘INT’ and the other position EXT.
When the jumper E5 is in position INT, then the transmitter will ignore any ON or OFF remote controls. This
remote controls can either come from the serial communication program or from the external remote control
connector on the rear of the MXi transmitter chassis. Please note that only the ON and OFF remote controls are
disabled and the AGC raise/lower and Vswr reset commands will still be operational. In this mode the transmitter
can only be turned ON or OFF via the front panel button. This is mostly for maintenance purposes when the
technician is working on the transmitter and doesn’t want anyone to remotely turn it ON or OFF.
When jumper E5 is in the EXT position then remote controls are enabled, this is the normal factory setting as
shipped. Even when E5 is in the ‘EXT’ position, the front panel button will still shut the transmitter OFF if it is
placed in the OFF position but when the front panel button is pressed in then the remote ON/OFF controls are
enabled. The MXI transmitter records the last known requested ON/OFF state from the remote control and will
cause the transmitter to enter into that state. If the operator last issued a remote OFF command then the remote
state of the transmitter would be OFF and if the operator last issued an ON command then the remote state of the
transmitter would be OFF. This is done to insure that when remote control is enabled and an AC power failure
occurs, then upon restoration of AC power the transmitter will return to the ON/OFF state is was in prior to the AC
power failure. This is necessary since the remote ON/OFF commands are momentary closures and are not
present all the time.
E
XTERNAL
R
EMOTE
C
ONTROL
C
ONNECTIONS
External remote controls are intended to interfacing to a third party remote control vendor such as Moseley or
Gentner if such systems are installed or available at the transmitter site. These external controls function in
parallel with the serial remote commands implemented with the Larcan supplied remote control program.
These remote signals are available on the 15-pin D-connector labeled Telemetry on the rear panel of the
MXi005U transmitter. The remote controls can be broken down into four categories, control inputs, status
outputs, telemetry outputs and interlock as follows:
Remote Command Inputs
There are only three remote commands available to the operator, these being TX ON, TX OFF and VSWR Reset.
In the table of remote signals, all remote commands have an RC_prefix.
All remote controls are active low, opto-isolated inputs configured as shown at left, all of which require a GROUND
for assertion and the activator to be able to sink 15mA or more for at least 200ms to accomplish reliable keying.
Each of these is current-limited by an individual resistor. A ground reference pin is provided at pin 12 to ease the
interface task since all these remote commands are active low and require a short to ground.
PUB06-76 Rev 2 July 18, 2007
06-76-4
MXi005U Operations and Maintenance
