VXI VT1433B - Manual (Page 64)

Parameter Settings
Many parameters are channel-dependent, meaning that each channel can be set
independently of the others in the module. Other parameters are
module-dependent; changing a module-dependent parameter for a channel will
change it for all channels on that module. For example, changing blocksize, a
module-dependent parameter, for input channel 3 will also change the block size
for all other channels in the same VT1433B module as channel 3.
When possible, parameters are written to the hardware as soon as they are
received. Sometimes, the parameter can’t be written to the hardware until the
start of a measurement; in this case the value of the parameter is saved in RAM
in the VT1433B module until the measurement is started with
hpe1432_initMeasure. Some parameters can be changed while a measurement is
running, but many do not take effect until the next start of a measurement.
Measurement Initiation
This section describes the measurement initiation process in the VT1433B.
The measurement initialization states and the corresponding Sync/Trigger line
transitions (with ‘H’ for high, ‘L’ for Low) are:
The module enters the TESTED state after a reset. In this state, all of the
module parameters may be set. The VT1433B stays in the TESTED state until it
sees a high-to-low transition of the Sync/Trigger line.
VT1433B User's Guide
Using the VT1433B
3-26
Settling Tested Booting Booted Pre-arm Idle
H
Sync/Trigger Line
L H L H L H L
Figure 3-8: Measurement initialization