Ttl Status Signals - Princeton Instruments PhotonMAX System Manual

Chapter 6

TTL Status Signals

The I/O (Input/Output Status) connector
on the rear of the PhotonMAX provides
information about trigger function, DAC,
and TTL signals. Inputs must be at least
3.15 V for a high and less than 0.9 V for
a low. This section will describe the
functions of the EXPOSE OUT,
FRAME READOUT, and SHUTTER
OUT signals that are provided by the
camera and can be used to control
external devices. For more information
about the I/O connector, refer to
"I/O Connector Pinout", starting on page 84.
•
•
•
SHUTTER OUT
EXPOSE OUT
FRAME READOUT
Figure 48. Comparison of SHUTTER OUT, EXPOSE OUT, and FRAME READOUT Levels
Advanced Topics
Shutter Out: TTL output for timing of external shutter driver. Signal is high
during Shutter Open Compensation Time and exposure time. The pin does not
provide power to drive the shutter directly, so an external shutter drive controller
is required.
Expose Out: A high level on this output indicates that the camera is exposing
(integrating).
Frame Readout: Active high. A high level on this output indicates that data is
being transferred.
t t
exp
O
Open
First
exposure
Figure 47. PhotonMAX Rear Panel and I/O Cable
t t
R
C
Close Open
Data Second
transfer exposure
Read
t = Shutter Open Compensation Time
O
t = Shutter Close Compensation Time
C
t = Exposure Time
exp
t = Readout Time
R
Close Open
Data Last
transfer exposure
Read
59
Close
Data
transfer
Read