Ocean Optics SAD500 Communications and Control - Manual (Page 9)

9
Read All Data
Description: Transmits all data from either fast or slow memory. For fast memory, the current pixel mode is
utilized. For slow memory, the pixel mode in effect when that scan was stored is utilized. After transmitting
each scan, the user must send the Scan Received OK command (O) before transmitting the next scan.
Command Syntax: R{ DATA WORD }
Value:
1 = Read data from fast memory
2 = Read data from slow memory
Response: ACK or NAK
Default value: N/A
Consider issuing the Read Out 1 Scan from Memory command (see page 8) rather than issuing this
command. Once initiated, this command continues to execute until all data is transmitted.
Spectral Acquisition
Description: Acquires spectra with the current set of operating parameters. When executed, this command
determines the amount of memory required. If sufficient memory does not exist, an ETX (ASCII 3) is
immediately returned and no spectra are acquired. An STX (ASCII 2) is sent once the data is acquired and
stored. If the Data Storage Mode value is 0, then the data is transmitted immediately.
Command Syntax: S
Response:
If successful, STX followed by data
If unsuccessful, ETX
The format of returned spectra includes a header to indicate scan number, channel number, pixel mode, etc.
The format is as follows:
WORD 0xFFFF – start of spectrum
WORD channel number
WORD scan number
WORD scans in memory
WORD integration time in milliseconds
WORD integration time counter -- see the Read Integration Counter command (t) for details
WORD pixel mode
WORDs if pixel mode not 0, indicates parameters passed to the Pixel Mode command (P)
WORDs spectral data
WORD 0xFFFD – end of spectrum
WORD checksum (optional)
Trigger Mode
Description: Sets the S2000’s and S1024DW’s external trigger mode to the value specified by driving the
appropriate TTL signals onto the S0 and S1 lines.
Command Syntax: T{ DATA WORD }
Value:
0 = Normal – Continuously scanning
1 = Software trigger
2 = External synchronization
3 = External hardware trigger
Response: ACK or NAK
Default value: 0
When using external trigger modes (Values 1 through 3), the SAD500 and spectrometer require a
trigger event after the Spectral Acquisition command (S) is issued.