Spectral Instruments Series 800, User Manual, Page: 25 / 70

Spectral Instruments
Pt # 2500- 25
camera has reached the selected operating temperature the “
COOL
” LED glows but not
as brightly.
2.5 Commanding The Camera
The camera accepts a number of commands and parameters from the host computer. The
commands are all single ASCII letters, which can be upper case or lower case. No
termination characters, such as carriage return and or line feed, are necessary to initiate
the command. Only those characters that are part of the command set are valid. The
command set is available from Spectral Instruments upon request as part number 1870.
Termination characters are treated as invalid commands and thus should
never be
transmitted. For any valid command, the command is echoed back to the host, the
command is executed and then a reply of an ASCII Y is sent, to indicate successful
completion of the command, or a reply of an ASCII N is sent to indicate that the
command is invalid. Some variations occur in exactly when the various Y responses are
transmitted to the host computer depending upon the activity commanded.
If a command requires a parameter or parameters, it (they) must be sent as 32-bit binary
word(s) with the most significant byte sent first, immediately after the command letter
echo is received. The camera knows from the command what sort of parameter(s) is/are
expected and waits for transmission of requisite number of bytes. The parameter(s) is/are
not echoed. The camera waits for the number of bytes that are expected for the command
so it is important that every command that requires a parameter be followed by the proper
number of bytes. After the parameter(s) is/are received the terminal Y or N response is
returned. If a parameter is out of range for that command a N reply is issued and the
command is not executed.
Commands from the host computer, that ask the camera for status or configuration, send
the information after the command is echoed. These numbers are also 32-bit and are sent
with the most significant byte first. After the parameters are sent the Y or N is sent. The
camera communications protocol is documented also under SI Part Number 1870.
2.6 Initial Tests
To assure the camera is functional even before it is cooled, it is reasonable to run through
initial imaging tests while the camera is cooling down. Final performance metrics cannot
be undertaken until the camera has stabilized at its regulating operating temperature.
There are several configurations the camera can assume. For some of them it is not
possible to “take an image” without fully integrating the camera into the application
apparatus. This manual uses tests for which a dark environment is sufficient.
The following also assumes that the SI-Image program is used to run the camera. Any
other operational software will work as long as the equivalent camera operations can be
commanded from within that software.