9.4.3 Exposure
The 11bit argument of the EXP command sets the camera exposure by controlling an internal
“exposure bus” which is made up of 11 data bits DB[10:0]. The power-on default value of EXP is
001. An exposure command with the syntax "EXP 7FF" would set the exposure to the maximum
value (all bits set "High"). The argument of the EXP command has different increments depending
on the mode of the camera .. in hi-spd shutter exposure modes, the EXP increments are one-H-line-
period, in NFR mode, the increments are one-frame-periods and in ULT mode the increment is
10seconds.
NOTE:
the argument of the EXP command is offset by 1 in all modes.
For example, EXP 000 in NFR mode gives 1-frame exposures
EXP 000 in hi-spd shutter modes gives 1-line exposures
EXP 000 in ULT mode gives 120-frame exposures.
9.4.4 Modes
The camera modes are set via 4 internal signals, corresponding to MC3, MC2, MC1, MC0. The
syntax for the MDE command is "MDE XYZ" where XYZ can be any of the three character
codes shown in the table below. The exposure bus DB[10:0] signals are driven by EXP{arg} in
all modes. The MC[3:0] signals are set as shown by the table below:
MC
3 2 1 0
Code Description VRST_INT
0 0 0 0 2:1 Binning; BIN 21 Hi Z
0 0 0 1 2:2 Binning; BIN 22 Hi Z
0 0 1 0 4:4 Binning; BIN 44 Hi Z
0 0 1 1 8:8 Binning; BIN 88 Hi Z
0 1 0 0 Slow scan, divide PIXCLK by 2; SLW 02 Hi Z
0 1 0 1 Slow scan, divide PIXCLK by 4; SLW 04 Hi Z
0 1 1 0 Slow scan, divide PIXCLK by 8; SLW 08 Hi Z
0 1 1 1 Unlock slow-scan & binning; SLW 01 OR BIN 11 Hi Z
1 0 0 0
RR
ormal mode with rese
Hi Z
1 0 0 1 HDO High speed shutter with discharge (one-shot) Hi Z
1 0 1 0 HNL High speed shutter without discharge Hi Z
1 0 1 1 HDL High speed shutter with discharge (continuous) Hi Z
1 1 0 0 ULT Ultra-long-term exposure Hi Z
1 1 0 1
FR "N" frame integration (low speed shutter) Hi Z
1 1 1 0 PDI Pulse driven exposure (internal, one-shot) Int. ¯¯|____|¯¯ sets exposure
1 1 1 0 PDP Pulse driven exposure (internal, periodic) Int. ¯¯|____|¯¯ sets exposure
1 1 1 0 PDX Pulse driven exposure (external) Hi Z
1 1 1 1
OR
ormal without rese
Hi Z
Pulse Driven Exposure (external): this is a "special" mode of operation in which the exposure of
the camera is set via a user-determined pulse. In the external (PDX) version of this mode, the user
supplies an external VRST_INT pulse – at the falling edge, the camera starts to integrate charge on
the CCD. When the pulse goes "High", the vertical counter within the camera is reset and frame
readout begins (it is the user’s responsibility to ensure that the "high" duration lasts for at least one
frame read-out (83msec).
Pulse Driven Exposure (internal): this is a "special" mode of operation in which the exposure
of the camera is set by the low-duration of a user-determined pulse.
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