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6102
3.2.2.6. Parameter P9: Fault Accept by External Trigger
This parameter is a switch to authorize the recovery from a fault by the external trigger, available only if
P5 = 0.
3.2.2.7. Parameter P15: High Voltage Value Correction
This parameter can be used to adjust the displayed voltage on the front panel to correlate to the meas-
ured high voltage at the applicator tip. A small difference can exist between high voltage units because
of the accuracy of the resistors used. This difference should not /- 3 kV.
3.2.2.8. Over-Current Programming Parameters MP19, SP19, TP19, RP19
The over-current programming evaluates the current draw while the controller is active. The GNM 100
has two over-current protection schemes. The first scheme is to regulate the voltage when the current
reaches its maximum value; this scheme is referred to as limitation and utilizes all of above-mentioned
parameters. In the second scheme if the current exceeds the maximum allowable value the controller is
faulted and the front panel displays “I overflow” and only utilizes the parameter SP19.
MP19: Current Management
This is a switch used to select which type of current management the user desires to use.
The front panel display shows which current management scheme is in use by Il for limitation and Io for
fault management. Il and Io are high voltage unit dependent and can be adjusted below their maximum
values in the user menu.
SP19: Minimum Current Return Threshold
This value is the minimum current return value that must be obtained before the current management
system is enabled.
This value is expressed in micrometers and the adjustment range depends on the characteristics of the
high voltage unit. Increments are in multiples of one or five micro amperes
TP19: Fault Delay
This value is the maximum time during which the system accepts the return current above the value
defined in Io. This value is expressed in milliseconds (ms) and incremented in steps of 4 milliseconds.
RP19: Current Ramp Function This is a switch, which enables the maximum allowable current to be
lower during the initial voltage ramp.
The system creates an imaginary voltage ramp incremented by one unit per each cycle of the program
until the maximum high voltage unit voltage or set point is reached. During this ramp the maximum allow-
able current draw is adapted to the imaginary voltage ramp by the relation:
Allowable Current = Io * Imaginary Set Point / high voltage units Maximum Voltage
MP19 = 0
Current Management by Limitation
MP19 = 1
Current Management by Fault
SP19
Minimum Adjustment
1 to 5 mA
SP19
Maximum Adjustment
Io
TP19
Minimum adjustment
4 ms
TP19
Maximum adjustment
996 ms
RP19 = 1
Enables the ramp programming
RP19 = 0
Disables the ramp programming
