User Manual

GWMT Transmitter Manual Chapter 4: Installation and Operation 11
continuously updated with the status of the transmitter; if the transmitter turns off due to an error
condition, this will be displayed on line 4.
Display Control
There are two types of control for the LCD: Backlight ON/OFF, and Contrast Adjust. The
Backlight key toggles the LCD backlight on and off.
If the LCD is hard to read due to poor contrast, adjust the contrast as follows:
 If the LCD characters are dim or not visible, hold the Enter key down and repeatedly press
the Down Arrow key (↓) until the characters are dark enough.
 If the LCD characters and background are too dark, hold the Enter key down and repeatedly
press the Up Arrow key (↑) until the background is light enough.
Error Codes
The unit provides several diagnostic messages to aid in debugging; consult your Grayson
Wireless representative if error messages appear.
 PLL not locked: The synthesizer has lost phase lock.
 Out of Range: The value entered is out of range (either frequency or amplitude.)
 Press FREQ or AMP first: The user tried to use the up or down arrows keys without
selecting Frequency (FREQ) or Amplitude (AMP) first.
 ALC Out of Range: Power amplifier is not under leveling loop control.
 Low Battery: The battery voltage is less than required (about 11 Volts)
 RefDAC out of range: The internal reference has failed.
 Bad EEPROM Checksum: EEPROM data is invalid.
 Need to Calibrate: The unit has not been properly calibrated.
 PA Over-temperature: The power amplifier is too hot (about 85 degrees C)