SU320CSX
4110-0446, Rev. C
Page 55 of 96
© 2017 UTC
Aerospace Systems
Date Printed: 3-Jan-2017
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Command
PIXCLK:MAX?
Parameters
none
Return Values
value
Range
0 to 4294967295 (4,294,967,295)
Type
unsigned integer
Example
PIXCLK:MAX? -- query command
20750000 -- return value
5.12.
Frame and Exposure Control Commands
The internally timed exposure period in seconds is given by the following relation:
EXPPERIOD = (EXP + 28) / (PIXCLK:MAX) (seconds)
Where PIXCLK:MAX returns 20750000Hz (20.75MHz) and where EXP is a clock count parameter set
using the EXP command. 28 clock cycles are added to the exposure setting value to produce the true
exposure duration to account for clocking overheads of the FPA. The maximum exposure time for a
particular frame period is equal to the frame period, less the FPA required minimum dead (non-
integration) time of two row read times for the CSX.
30 μs is the absolute minimum recommended integration time, and 200 μs is the suggested minimum
integration time.
The internally timed frame period is given by:
FRAMEPERIOD = FRAME:PERIOD /PIXCLK:MAX (seconds)
The exposure period and frame period specified must be compatible with each other or a command error
will occur. Therefore, knowledge of the current exposure and frame periods are required and the order in
which the exposure and frame period are changed is crucial for success. Going from a short exposure and
frame period to a longer exposure and frame period requires first increasing the frame period and then the
exposure period, while going in the opposite direction requires shortening the exposure period first.
When the camera is set to operate in an externally triggered timing mode the exposure and frame period
settings may not apply. (See Section 5.13 for a description of supported triggered timing modes.)
5.12.1.
Set Exposure Period
Description
Sets EXPPERIOD, which controls the exposure time (see
equation).
Setting Type
Operational
Command
EXP
value
Parameters
value
Return Values
none
Range
1 to 16777214
Type
unsigned integer
