User guide

Model 577 Operating Manual 20
12.1.1 Module Errors
If a channel on any AT45 module is over-driven, the channel will disable itself and the system will indicate an error
on the module. The error will not clear until the user fixes the error causing condition and presses the Clr Err soft
key, or power cycles the instrument. The overdriving protection is limited to low resistance errors not to direct
shorts to ground. Damage to the output will occur when driving into short circuits. Module errors may occur due
to any of the following:
- Over current.
- Over temperature.
- Internal hardware.
12.1.2 System Limit Error
The system will not allow the Lo Impedance enabled AT45 channels to exceed 150 V total amplitude. If this
situation occurs, the “Over-Driving Unit” error is displayed and the currently adjusting amplitude is reduced to the
150 V enabled channel limit.
12.2 Voltage Change Timing
The channels adjustable voltage changes very quickly when adjusting from a lower voltage to a higher voltage but
changes slowly when changing from a higher voltage to a lower voltage. It takes approximately 30 sec to change
from 45 V to 4.0 V so caution must be taken when adjusting the voltage to a lower voltage tolerant circuit.