VT1433B User's Guide
Module Description
Status LEDs
Fail: This is the standard VXI “Failed” indicator. It lights briefly when powering up and normally goes out after a few seconds. If it stays on it indicates a hardware failure in the module.
Acs: This is the standard VXI “Access” indicator. When it is on, it indicates that another device on the bus is contacting the module, for example to transfer data or read registers.
Trigger: This LED flashes on each time the measurement triggers, so when it is blinking it indicates that the measurement is triggering.
If the VT1433B has the Tachometer option, this LED is defined differently. See the chapter: The Tachometer Option
SMB Connectors
FExSamp: This is an input connector for an external sample clock. The sample clock must be TTL level and have a frequency between 40.96 kHz and 100 kHz. Internally this frequency can be decimated.
Cal: This connector is used for calibration. It can be configured to output a calibration signal or to accept an input calibration signal. See the calibration section in this chapter.
ExTrig: This allows for an external trigger input to the VT1433B. The input signal must be TTL, other characteristics can be defined in software. ExTrig can be enabled or disabled in software.
Input Connectors (One or Two)
These connectors are attached to the cables from an