Ocean Optics Ventana User Manual

Ventana Data Sheet

Description

The Ocean Optics Ven tana ser ies of hig h-sensitivity spectrometers maintain high sensitivity and
throughput for low-light level applications such as Raman analysis or fluorescence with laser
excitation without the need for long integration times or high-power excitation sources. This
spectrometer uses an HD Volume Phase Holographic (VPH) Grating, low f/# design and anti­reflection coatings to allow more of the coupled light into the spectrometer. The internal optics have
been selected to minimize light loss and provide superior image quality. The Ventana models include
the following:

• Ventana-785-Raman -- preconfigured for 785 nm excitation Raman measurements; includes a

cooled (down to 15 °C) NIR-enhanced, back-thinned detector with low noise electronics

• Ventana-532-Raman -- preconfigured for 532 nm excitation Raman measurements

• Ventana-785L-Raman -- preconfigured for 785 nm excitation Raman measurements with

integrated 785 nm laser; free-space coupling to maximize sensitivity; front-end laser matches
the ƒ/1.3 spectrometer input to maintain maximum efficiency; hard-coated filters used to
maximize transmission and minimize Rayleigh scattering

• Ventana-VIS-NIR -- preconfigured with 430-1100 nm bandwidth, 50 micron slit; low f/2;

configuration optimized for low signal VIS-NIR measurements (430 to 1100 nm) such as
fluorescence; low f/# with custom lens design and optic coatings providing superior image
quality and high transmission

All model Ventana spectrometers use the Hamamatsu S11510-1006 back-thinned, reduced etalon
detector except for the VIS-NIR version, which uses the Hamamatsu S10420-1006 detector. For
complete details on these detectors, visit www.Hamamatsu.com.

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Ventana Data Sheet

In addition to the Ventana spectrometer s, the Ven tana-785-Probe offers a Raman-coupled fiber probe
for 785 nm excitation; FC connector (excitation), SMA connector (collection); 11.0 mm working
distance; 250-2000 cm-1; comes with 600 µm 0.39 NA detection and 100 µm 0.22 NA excitation
fibers to maximize sensitivity.

Features

• HD Volume Phase Holographic (VPH) Grating

• Electrical Performance

• 16 bit A/D converter

• Communications: USB

• Software compatibility:

• OceanView (1 complimentary license included with purchase)

• SpectraSuite

• OmniDriver (sold separately)

• USB Programmer (available free from Ocean Optics)

• SeaBreeze (sold separately)

• Optical input: SMA 905

• Regulations:

• CE Mark

• RoHS

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Ventana Data Sheet

Specifications

CCD Detector Specifications

Specification Ventana 532 Ventana 785 Ventana 785L Ventana Vis/NIR

Detector Hamamatsu S11510-10 06 Bac k-thinned NIR-enhanced CCD Hamamatsu

S10420-1006 Back­thinned CCD

Detector
active area
(mm)

Pixel format 1024 x 64
Pixel size 14 µm square
Well depth 300 Ke­Read noise 6 e- RMS
Dynamic

range
CCD QE 78% peak, 60% average in Raman 75% peak
CCD Cooling None

14.336 x 0.896

17000:1 (Typical)

°C

15

None

Ventana Spectrometer Specifications

Specification Ventana 532 Ventana 785 Ventana 785L Ventana VIS/NIR

Dimensions
(LxWxH)

Weight 0.9kg (2 lb)

Temperature
Operation

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170 mm (6.7 in.) x
110 mm (4.3 in.) x
50 mm (1.9 in.)

0 to 50

°C (noncondensing)

125 mm (4.9 in.) x
110 mm (4.3 in.) x
50 mm (1.9 in.)

127 mm (5 in.) x

158.75 mm (6.25
in.) x 50.8 mm (2
in.)

Spectrometer:1.2kg
(2.6 lb)

Power Supply:

0.5kg (1.10 lb)

5 to 45
(noncondensing)

°C

170 mm (6.7 in.) x
110 mm (4.3 in.) x
50 (1.9 in.)

0.9kg (2 lb)

0 to 50°C
(noncondensing)

Ventana Data Sheet

Specification Ventana 532 Ventana 785 Ventana 785L Ventana VIS/NIR

Power 12 VDC

Gratings

Diffraction
efficiency

1600 lpmm HD
VPG

85% peak at 610
nm

1625 lpmm HD VPG

83% average for S&P

450 lpmm at CWL
580 nm

65% average for

S&P
Optical input SMA 905
Slit Size 50 µm
Fiber

diameter
Resolution

(FWHM) cm
Resolution

(FWHM) nm

-1

-1

20 cm

10 cm

0.6 nm 0.7 nm

Optimized for 600µm, NA = 0.39 fiber input

-1@

810 nm N/A

@

810 nm 4.0 nm

f/# 1.3 2.0
Signal-to-

noise ratio
Integration

time

~550:1 (Typical)

22 ms – 4 min

Wavelength
Range

533 – 690 nm 800 – 940 nm 800 – 940 nm 430 – 1100 nm

Interface USB 2.0 (no external accessory connector access)

Ventana 785L Laser Specifications

Specification Value

Wavelength 785 nm
Working Distance 21.95 mm
Image Spot Size 10 mm
Sample Spot Size 75 mm
Laser type Single-mode laser diode stabilized with VBG

Laser control Enable/disable
Laser power stability < 1% after 30 seconds from being enabled

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Ventana Data Sheet

Mechanical Diagrams

Ventana 532-Raman

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Ventana Data Sheet

Ventana 785-Raman

Ventana Spectrometer Detector

The Ventana contains a Hamamatsu S11510-1106 two-dimensional CCD. The Ventana electronics
only support reading out the device as a 1-D array (e.g., all rows are summed together on chip). The
structure of the Ventana spectrometer Hamamatsu CCD is shown below. The device has 2048 x 64
active pixels and a total of 2068 x 70 pixels.

Pixel Definition

The following is a description of all of the pixels:

Ventana Pixels

Pixel Description

0 Unusable
1–3 Dark
4–9 Bevels/unusable
10–2057 Spectrum
2058–2063 Bevels/unusable
2064–2067 Dark

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Ventana Data Sheet

Ventana CCD Device structure (64 active vertical pixels and 2048 active horizontal pixels)

Ventana USB Port Interface Communications and Control Information

The Ventana is a microcontroller-based Miniature Fiber Optic Spectrometer that can communicate via
the Universal Serial Bus. This section contains the necessary command information for controlling
the Ventana via the USB interface. This information is only pertin ent to user s who wish to not utilize
Ocean Optics 32 bit driver to interface to the Ventana. Only experienced USB programmers should
attempt to interface to the Ventana via these methods.

Hardware Description

The Ventana utilizes a Cypress CY7C68013A microcontroller that has a high speed 8051 combined
with an USB2.0 ASIC. Program code and data coefficients are stored in external E
loaded at boot-up via the I
SRAM. Maximum throughput for spectral data is achieved when data flows directly from the external
FIFO’s directly across the USB bus. In this mode the 8051 does not have access to the data and thus
no manipulation of the data is possible.

2

C bus. The microcontroller has 8K of internal RAM and 64K of external

2

PROM that are

USB Info

Ocean Optics Vendor ID number is 0x2457 and the Product ID is 0x5000.

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Ventana Data Sheet

Instruction Set

Protocol Design

The binary command protocol for the Ventana Spectrometer has the following design characteristics:

• Provides information so that the host does not need to know the state of the device to read the

message.

• Contains a distinct header and footer to fully bracket transfers.

• Provides an abstract interface to the device. All timing is represented in standard units rather

than clock divisors. A specific outcome is achieved via a single mechanism.

• Stores calibration information (wavelength, nonlinearity coefficients, etc.) in distinct

commands rather than EEPROM slots.

Ventana Command Protocol

There are two types of messages in this protocol:

• "commands" that do not return any information

• "queries" that cause the device to return information

When developing a device driver that will communicate with the Ventana, the fact that some messages
generate a response (including a status indication) and others do not can cause design problems. The
simplest approach to creating a driver for this protocol is to have all message types generate a reply.
This allows a single message read to be performed after every message write, and if the response
indicates an error, then the driver can recover immediately rather than finding the error later when it
expects a response to some new query.

The "flags" field in the message header (starting at byte offset 4) has an "acknowledgment (ACK)
requested" bit (bit 2). If this bit is set to 1 for every "command", and left at 0 for every "query", then
all communications with the Ventana will become pre dic table read /w rite tran s acti ons. The imm ediate
reply allows the host driver to avoid changing its state until it has received confirmation that the last
operation succeeded or failed. This makes driver design much easier than the alternative.

It is recommended that an Ventana protocol driver implement two functions:

• send_command_to_device() which takes a message type and an optional payload, and returns

a simple pass/fail result based on the ACK or NACK flag in the response. This should set the
"ACK requested" bit in every message it emits;

• query_device() which takes a message type and optional payload and returns a payload (e.g. a

byte array) which can be NULL if the response was a NACK. This must not set the "ACK
requested" bit because to do so would generate a spurious ACK in addition to the expected
response.

By using these two functions to encapsulate all transfers to the Ventana, the programming model is
kept very simple.

Message Layout

All multi-byte fields are little-endian (LSB first). Each message in the binary protocol is laid out as
follows:

1. A 44-byte header

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Ventana Data Sheet

2. An optional payload

3. A 16-byte checksum block

4. A four byte footer

The header, checksum, and footer are 64 bytes total. For simple messages, the command or response
is embedded in the header so only a single packet is required. For more complex messages, the header
and footer add a single USB packet as overhead to the transfer.

Header

The message header is structured as follows:

Offset
(Bytes)

Field Size

(Bytes)

Valid Values Notes

0 Start Bytes 2 0xC1C0 Chosen for the following reasons:

High bits set, so not likely to occur in ADC data

less than 16 bits wide or message type fields

When concatenated with the tail of a previous

message, creates a distinct sequence

Note: Do not reverse this byte order.

2 Protocol

Version

2 0x0000 –

0xFFFF

Initially set to 0x1000. The host should only send
messages known to be supported in the reported
version of the protocol. Subsets of this protocol may
be specified for other devices using a version less
than 0x1000. The device may reject messages with a
specified protocol it does not recognize.

4 Flags 2 0x0000 –

0xFFFF

Bits in this flag are assigned as follows:

Bit 0: response to earlier request (message type is set

equal to request type). Set by device.

Bit 1: acknowledgment (ACK) if previous message

included request for ACK. Set by device.
Bit 2: acknowledgment (ACK) requested. Set by Host.
Bit 3: negative acknowledgment (NACK). May be sent if

previously sent message type is unknown or otherwise

invalid. Message type and regarding fields will be set to

the type that caused the error. Set by device. Error

Number field contains reason for NACK.
Bit 4: exception occurred. Indicates that although the

message itself was valid, the device encountered a

hardware problem that may have invalidated the result.

Error Number will be set to explain, if possible. Set by

device.
Bit 5: The message protocol used by the caller is

deprecated. If set, an older version of the protocol has

been detected (version less than 0.1100). Set by the

device.

6 Error

Number

2 0x0000 –

0xFFFF

Only set by the device. Indicates whether the previous
request was successful. Only set to be non-zero if at
least one of the following flags is set: NACK or
exception. Only one value can be set, even if multiple
errors were detected. Values:

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Ventana Data Sheet

0: Success (no detectable errors)

Data Length field, and there is no payload. If a

Offset
(Bytes)

Field Size

(Bytes)

Valid Values Notes

1: Invalid/unsupported protocol
2: Unknown message type
3: Bad checksum
4: Message too large
5: Payload length does not match message type
6: Payload data invalid
7: Device not ready for given message type
8: Unknown checksum type
9: Device reset unexpectedly
10: Too many buses (Commands have come from too

many bus interfaces)
11: Out of memory. Failed to allocate enough space to

complete request.
12: Command is valid, but desired information does not

exist.
13: Int Device Error. May be unrecoverable.
100: Could not decrypt properly
101: Firmware layout invalid
102: Data packet was wrong size (not 64 bytes)
103: hardware revision not compatible with firmware
104: Existing flash map not compatible with firmware
255: Operation/Response Deferred. Operation will take

some time to complete. Do not ACK or NACK yet.

8 Message

Type

12 Regarding 4 0x00000000

16 Reserved 6 For future expansion.
22 Checksum

Type

23 Immediate

Data
Length

24 Immediate

Data

4 0x00000000

–

Each message type represents a command. See

Message Types

.

0xFFFFFFFF

Arbitrary host-defined data. Any response generated
–
0xFFFFFFFF

by the device will have the same value in its

Regarding field. This can be used by the host to

match responses to requeVentana if transactions are

split up.

1 0x00 – 0x01 Valid t ypes:

0: no checksum (must still provide a block of 16

bytes after the payload, but they can be zero).

1: MD5 (fully fills the 16 byte checksum block)

1 0x00 – 0x10 Total number of bytes used in the Immediate Data

field (see below).

16 Provides an alternative to specifying a payload so

commands with small operands can fit within a single

USB packet. If this field is used, the number of bytes

containing valid data must be set in the Immediate

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Ventana Data Sheet

payload is used, this field is ignored.

Offset
(Bytes)

40 Bytes

Field Size

(Bytes)

4 0x00000000

Remaining

Valid Values Notes

Includes the payload, if any, plus the checksum and
–
0xFFFFFFFF

footer. This is included for RS-232, such that a

constant-sized header could be read (including this

field) followed by another read for the remainder of the

message. Payload length must be computed as this

field minus the checksum and footer length. Ventana

may reject any message too long for it to process

internally and return a NACK.

The header can be represented as a C struct as follows (assuming that the int type is 32 bits long):

struct ooi_binary_protocol_header {
unsigned char start_bytes[2]; /* = { 0xC1, 0xC0 } */
unsigned short protocol_version; /* = 0x1000 */
unsigned short flags;
unsigned short errno;
unsigned int message_type;
unsigned int regarding;
unsigned char reserved[6];
unsigned char checksum_type;
unsigned char immediate_data_length;
unsigned char immediate_data[16];
unsigned int bytes_remaining;
};

Payload

After the standard header, a payload may be provided. The payload contains data required by the given
message type. The format of the data within the payload depends on the message type. Note that a
payload is not required if operands will fit in the Immediate Data field of the header. The length of the
payload must be computed from the Bytes Remaining field in the header, given that the checksum and
footer are of a constant length:

Payload length = Bytes remaining – 20

The Ventana may populate the Immediate Data field or the Payload as appropriate for the length of the
data being returned, regardless of the message type. Host programs decoding this protocol should
always be capable of checking both areas in any response.

Checksum

A 16-byte block must appear after the payload (if any) to contain checksum data. This block is
required even if no checksum is used (according to the Checksum Type field) or if the checksum does
not require the full 16 bytes. The unused parts of the block are for padding to ensure the message
length is consistent. This protocol does not support checksums longer than 16 bytes, e.g. SHA, but the
intent of the checksum is to detect bit errors, not to prevent tampering or to provide cryptographic
assurance. The checksum may not be necessary for USB but may be useful for buses that do not
provide data integrity guarantees, such as RS-232.

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Ventana Data Sheet

If a checksum is used, it will be computed starting with the start byte of the header and continuing
through the last byte of the payload. The length of the checksum and footer will not be included in the
checksum (i.e., for MD5, which includes the total data length as a salt value).

Footer

After the checksum block, a 4-byte footer is provided. The footer has a constant value of
0xC5C4C3C2. Do not reverse the order of the footer.

Message Types

The binary protocol divides up the 4.29 billion possible message types into categories and
subcategories in a hierarchy. The most significant bits represent the more abstract categories, while the
least significant bits represent subcategories and the commands. The 32-bit message type is split into
three blocks, 0xXXX YYY ZZ, as follows:

XXX: top-level category or feature. 4096 of these may exist.
YYY: subcategories within the feature. 4096 of these may exist for each category.
ZZ: specific commands for the subcategory. 255 of these may exist for each subcategory.

The top-level categories (XXX) are initially defined as follows.

0x000: General device characte rist ics
0x001: Spectrometer feature (control of detector and ADC, pixel calibrations and corrections)
0x002: GPIO feature (configuration and control)
0x003: Strobe features (single and continuous strobe timing)
0x004: Temperature

The subcategories and commands for each of these categories are described in the tables that follow.
Input and output data lengths that can be computed from the header (Bytes Remaining field) are not
shown. All multi-byte integer types will be returned in little-endian form at (lea s t significant byte
first). All data will be carried over Endpoint 1or Endpoint 2 IN and OUT unless otherwise stated.

Message Examples

The following is an example of how the Set Integration Time message type (0x001 100 10) can be
constructed based on the information provided in this data sheet:

Header

Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7

0xC1 0xC0 0x00 0x10 0x00 0x00 0x00 0x00
Start bytes Protocol version Flags Error number

Byte 8 Byte 9 Byte 10 Byte 11 Byte 12 Byte 13 Byte 14 Byte 15

0x10 0x00 0x11 0x00
Message type (0x00110010) Regarding (user-specified)

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x x x x

Ventana Data Sheet

Byte 16 Byte 17 Byte 18 Byte 19 Byte 20 Byte 21 Byte 22 Byte 23

0x00 0x04
Reserved

Checksum
type

Immediate
length

Byte 24 Byte 25 Byte 26 Byte 27 Byte 28 … Byte 39

x

LSB
Integration time (immediate data) Unused

x

x x

0 0 0

MSB

Byte
40

0x14 0 0 0
Bytes remaining

Byte
41

Byte
42

Byte
43

Optional
Payload

Not used for
this command

Byte 44…Byte 59 Byte 60 Byte 61 Byte 62 Byte 63

Checksum 0xC5 0xC4 0xC3 0xC2
Footer

The following is an example of how the Get And Send Corrected Spectrum Immediately message type
(0x001 010 00) can be constructed based on the information provided in this data sheet:

Header

Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7

0xC1 0xC0 0x00 0x10 0x00 0x00 0x00 0x00
Start bytes Protocol version Flags Error number

Byte 8 Byte 9 Byte 10 Byte 11 Byte 12 Byte 13 Byte 14 Byte 15

0x00 0x10 0x10 0x00
Message type (0x00101000) Regarding (user-specified)

x x x x

Byte 16 Byte 17 Byte 18 Byte 19 Byte 20 Byte 21 Byte 22 Byte 23

0x00 0x00
Reserved

Checksum
type

Immediate
length

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Ventana Data Sheet

Byte 24 … Byte 39

unused

Byte
40

0x14 0x00 0x00 0x00 Checksum 0xC5 0xC4 0xC3 0xC2
Bytes remaining Footer

Byte
41

Byte
42

Byte
43

No
payload

Byte
44…Byte 59

Byte
60

Byte
61

Byte
62

Response

Header

Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7

0xC1 0xC0 0x00 0x10 0x01 0x00 0x00 0x00
Start bytes Protocol version Flags Error number

Byte 8 Byte 9 Byte 10 Byte 11 Byte 12 Byte 13 Byte 14 Byte 15

0x00 0x10 0x10 0x00
Message type (0x00101000) Regarding (user-specified)

Byte 16 Byte 17 Byte 18 Byte 19 Byte 20 Byte 21 Byte 22 Byte 23

0x00 0

x x x x

Byte
63

Reserved

Checksum
type

Immediate
length

Byte 24 … Byte 39

unused

Byte
40

0x14 0x08 0x00 0x00 Checksum 0xC5 0xC4 0xC3 0xC2
Bytes remaining Footer

Byte
41

Byte
42

Byte 43

Payload
(2048
bytes of
spectral
data)

Byte
2092…Byte
2107

Byte
2108

Byte
2109

Byte
2110

Byte
2111

General Device Commands

Message Type Purpose Input Data Output Data Notes

0x000 000 80 Get hardware

revision

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N/A Unsigned

byte

This value is sensed from the
hardware itself.

Request has no payload.

Ventana Data Sheet

Message Type Purpose Input Data Output Data Notes

Reply is a single byte.

0x000 000 90 Get host

interface
firmware
revision

0x000 000 91 Get FPGA

firmware
revision

0x000 001 00 Get serial

number

N/A Unsigned

short

N/A Unsigned

short

N/A String

Firmware version as binary coded
decimal. The same value should be
available through the USB descriptor
as the bcdDevice field.

Request has no payload.
Reply is a 2-byte integer (LSB first) of

the revision.
Firmware revision as a binary coded

decimal for FPGA

Spectrometer Commands

Message Type Purpose Input Data Output Data Notes

0x001 010 00 Get and send

corrected
spectrum
immediately

N/A Pixel

values

(integers)

This returns the intensity of every
pixel on the detector as LSB, MSB as
soon as it is available. There is no
payload in the request. The reply has
2048 bytes of payload. The pixel
intensities are corrected for
temperature drift and fixed-pattern
noise.

0x001 100 00 Get integration

time (µs)

0x001 100 10 Set integration

time (µs)

N/A Unsigned

32-bit

integer

Unsigned
32-bit
integer

N/A Input is 4 bytes for time in µs. Order is

LSB, …, MSB
No reply.
The minimum is 10.

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Ventana Data Sheet

Message Type Purpose Input Data Output Data Notes

0x001 101 00 Get trigger

mode

0x001 101 10 Set trigger

mode

0x001 801 01 Get wavelength

coefficient

0x001 801 11 Set wavelength

coefficient

N/A Unsigned

byte

Unsigned

N/A Input has 1 byte in the request for

byte

Unsigned
byte

IEEE

single-

precision

Unsigned

N/A Input is the order of the coefficient to

byte, IEEE
single­precision

trigger mode.
Valid trigger modes:
Mode 0 (default): integration begins

as soon as possible after request
Mode 1: integration or trigger delay

begins with a rising trigger edge
Mode 2: integration is internally

triggered to synchronize with
continuous strobe

No reply.
Request has 1-byte input data for

coefficient index starting with
wavelength intercept at index 0.

Reply has 4-byte float (LSB first).

set (indexing starts with wavelength
intercept at index 0), followed by an
IEEE single-precision float.

No reply.

0x001 811 01 Get nonlinearity

coefficient

0x001 811 11 Set nonlinearity

coefficient

0x001 831 01 Get stray light

coefficient

0x001 831 11 Set stray light

coefficient

Unsigned
byte

Unsigned
byte, IEEE
single
precision

Unsigned
byte

Unsigned
byte, IEEE
single
precision

IEEE single

precision

Request has 1-byte input for
coefficient index to retrieve. Reply has
4-byte float (LSB first).

N/A Input is the order of the coefficient to

set, followed by an IEEE single­precision float.

No reply.

IEEE single

precision

Input is the order of the coefficient to
retrieve

N/A Input is the order of the coefficient to

set, followed by an IEEE single­precision float

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Ventana Data Sheet

Message Type Purpose Input Data Output Data Notes

0x004 200 00 Get TEC

temperature

0x004 200 10 Set TEC

enable

0x004 200 11 Set TEC

setpoint

N/A IEEE

single-

precision

float

Unsigned
byte

IEEE
single­precision
float

N/A 0 = Disabled, 1 = enabled. Sets

N/A Specifies the setpoint, in degrees

Result is degrees Celsius.

whether thermo-electric cooler
attached to detector is enabled.

Celsius, of the TEC.

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