Antenna Drive Polarity And Limits - Dawn CONTROL-1500A Manual

Remote controlled antenna controller for single axis antennas

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CONTROL-1500A Single Axis Antenna Controller

mode, the Expert Access flag has been reset. If this occurs, set the Expert Access flag as

outlined in section 2.5.

3. In this step the polarity of the polarization motor and sensor wiring is checked.

The sense of polarization movement polarity is somewhat arbitrary. The polarization jog

keys are labeled CW and CCW. The polarization drive motor and position sense

potentiometer must be configured so that when the polarization is jogged CCW the

indicated position count must increase. If the sense of polarization motion is not correct,

the installer can either swap the motor DRIVE lines (J4 terminals 4 and 5) or swap the

potentiometer reference (REF) and return (RTN) lines (J4 terminals 1 and 3). Note that the

shield of the sensor cable must always be connected to the J4 RTN terminal.

To check the polarity of the polarization motor, the rotating feed's logical limits must be set

so that unrestricted movement of the feed is possible. To achieve this, the Feed CW Lim

CONFIG mode item must be set to 0 and the Feed CCW Lim CONFIG mode item must be

set to 1023.

The polarization motor may be jogged in MANUAL mode. Jog the pol motor and make

sure that movement is in the proper direction - position count decreasing for CW

movement, and increasing for CCW movement. Note that once the rotating feed limits

have been set as described above, there are no limits on polarization movement. The user

must be careful to not move the feed past a limit. Damage to the rotating feed, polarization

motor, or potentiometer may occur if the limits are exceeded. If the user attempts to jog the

polarization motor and no movement is detected on the position sense lines, or movement

is detected in the wrong direction, the Antenna Polarization alarm will activate. If a

polarization alarm is active, an error message (!! ANT POL) will flash on the bottom row of

the display, and the polarization drive will be disabled. The alarm can be de-activated via

RESET mode.

4. Once the polarity of the motor drive and sense lines have been verified, the pol limits may

be set. To set the limits, the pol motor is first jogged (via MANUAL mode) to the positions

where it is desired to set the limits. It is recommended that an assistant be stationed at the

antenna to ensure that the polarization motor's (or sensor's) mechanical limits are not

exceeded. In MANUAL mode, record the polarization position values that correspond to

the desired limits. Once the limit locations are recorded, set the limits via the CONFIG

mode Feed CW Lim and Feed CCW Lim items. The Feed CW Lim position must be less

than that of the Feed CCW Lim position.

3.4