VXI VT1433B, User Manual, Page: 135 / 203

LEDs and Connectors for the Tachometer Option
Status LEDs
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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.
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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.
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Trigger: This LED flashes on each time an edge is detected on the tachometer signal,
so when it is blinking it indicates that the tachometer signal is on. (For a VT1433B
that does not have the Tachometer option, this LED is defined differently.)
SMB Connectors
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Tach1: This is one of the two tachometer inputs. Tach1 cannot be configured as an
external trigger.
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Tach2: This is the second of the two tachometer inputs. Tach2 can also be configured
(via software) to be an external trigger input
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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 8-Channel Input (breakout
box) — two input connectors for each 8-Channel Input). They connect the input
signal to the VT1433B. Each connector carries four channels. Depending on
options, there can be one or two input connectors (four or eight channels).
VT1433B User's Guide
The Tachometer Option
7-5