Incorrect cone voltage readback on Xevo TQ Family - WKB10652

SYMPTOMS

• Cone voltage readback = 94 V  (set to 14 V)

ENVIRONMENT

• Xevo TQ Absolute
• Xevo TQ MS
• Xevo TQD
• Xevo TQ-S
• Xevo TQ-S cronos
• Xevo TQ-S micro
• Xevo TQ-XS

CAUSE

This is normal.

FIX or WORKAROUND

1. The cone voltage readback is the sum of the voltages on several components. For instance: Source offset, StepWave body gradient, StepWave head gradient, and Collision energy, in addition to the cone voltage setting. The set cone voltage is recorded in the experimental record correctly along with the readback value.
    
2. The best way to check if the cone voltage is working is to note its setpoint and readback and add 5 or 10 volts to the setpoint and ensure the readback moves appropriately. The same can be done for earlier lenses, ensuring that lens readback moves and that all downstream lens readbacks (such as the cone) move also.

ADDITIONAL INFORMATION