4
ISOMET
Gate (active high enables the RF amplifier)
PLC compatible opto-isolated input
Default condition is RF Off.
A high level (5V < V < 24V) will gate the RF
ON
.
A low level (0V < V < 4V), or not connected will gate the RF
OFF.
Digital Modulation (active high )
Provides high speed frequency selection of the RF output.
A TTL high level will select 40.00MHz ( Main 1st order beam “
ON”)
.
A TTL low level will select 50.67MHz (Main 1st order beam “
OFF”)
.
The amplitude level for either frequency is defined by the selected RF power adjustment POT.
RF Power Adjustment (POT set level)
The maximum RF power limit is set by one of two methods. The method is selectable by the user.
a) A manual adjust multi-turn potentiometer ‘PWR ADJ’ for each frequency.
Maximum RF power = fully clockwise
or
b) A quad 256 step digital potentiometer configured to give independent power control for 40
and 51.7MHz levels with common variable end limits
All 4 channels are used for power level control. RDAC0, RDAC1, RDAC2 and RDAC3
(see AD5254 data sheet). Levels are set remotely via an I2C compatible serial connection.
The slave address for the digital I2C potentiometer is at 0101100. (AD0 = AD1 = 0)
DC Power
A low impedance DC power supply is required. The operating voltage is +24Vdc only at a current
drain of approximately < 18A. The external power source should be regulated to
±
2% and the power
supply ripple voltage should be less than 200mV for best results. Higher RF output power is achieved
at 28Vdc.
