Table of Contents:
Relevant Devices
Description | Qty | Source | Part Number | |
|---|---|---|---|---|
Lamp Intensity Monitor Controller | 1 | Newport | 1830-R-GPIB | |
Lamp Intensity Monitor Detector | 1 | Newport | 818-SL/DB | |
RS-232 to Ethernet Adapter | 1 | Lantronix | UDS2100 | This is the version with two serial ports (and standard 9-pin RS-232 connectors) |
Relevant Functional Block Diagram
Most recent version. Going forward, lamp intensity monitor and its connections are not expected to change.
Software Actions
Action | Notes | |
|---|---|---|
| 1 | Single measurement. | That is, report the Wattage value the detector is currently reporting. Note calibration unit translation stage has to move detector into beam first. |
| 2 | Calculate average of ‘n' discrete single measurements taken ’t' seconds apart. | Average several single measurements together to smooth out measurement noise/detector variability. This value reported as telemetry (see below). This approach was used for measurements at SSL using a similar device; see example Python code at bottom of this page. |
Required Adjustable Settings
NOTE: device automatically switches from “LOCAL” to “REMOTE” mode when it receives a remote command through either the USB, RS-232C, or IEEE 488 GPIB interfaces.
Setting | When Needed | Notes | ||
|---|---|---|---|---|
Build | Observing | Maintenance | ||
Number of measurements 'n' to include in average. | YES | NO | MAYBE | Perhaps start with 10 |
Time delay 't' between measurements used for average. | YES | NO | MAYBE | Perhaps start with 0.5 seconds. |
Device setup parameters follow: | ||||
Set offset subtraction | YES | NO | MAYBE | Equivalent to “ZERO” button on device. KPF default should be ‘Z0’ (no offset subtraction). |
Set calibration wavelength | YES | NO | MAYBE | Equivalent to wavelength buttons on device. KPF default value should be 658 nm. Remote command might be 'W0658'. |
Set attenuator mode | YES | NO | MAYBE | “ATTN” button on device. KPF default should be set to ‘off’ (i.e. no attenuator in place). Remote command is ‘A0’ |
Set measurement units | YES | NO | MAYBE | Equivalent to “UNITS” button on device. KPF default should be Watts (remote command ‘U1'). |
Set averaging mode | YES | NO | MAYBE | Equivalent to “AVG” button on device. KPF default should be set to ‘Fast’ mode (no averaging by device). Remote command for ‘Fast’ mode is ‘F3’. |
Set audible beep on/off | YES | NO | MAYBE | Equivalent to “BEEP” button on device. KPF default should be ‘off’ (remote command ‘B0’) |
Set automatic range | YES | NO | MAYBE | Equivalent to “AUTO” range on device. KPF default should be auto-range (remote command ‘R0’). |
Turn display on/off | YES | NO | MAYBE | KPF default should be ‘off’ (remote command ‘K0’). Likely device produces less heat (and isn’t a light source) with the display off. |
Local lockout | YES | NO | MAYBE | I presume KPF default should be ‘locked’ while under remote operation (remote command ‘L1’) |
Required Telemetry
Parameter | Report Frequency | Purpose | Notes | |
|---|---|---|---|---|
| 1 | Source 1 intensity | TBC | Monitor calibration source outputs over time | Report this value if Source 1 is selected at octagon. |
| 2 | Source 2 intensity | TBC | Report this value if Source 2 is selected at octagon. | |
| 3 | Source 3 intensity | TBC | Report this value if Source 3 is selected at octagon. | |
| 4 | Source 4 intensity | TBC | Report this value if Source 4 is selected at octagon. | |
| 5 | Source 5 intensity | TBC | Report this value if Source 5 is selected at octagon. | |
| 6 | Source 6 intensity | TBC | Report this value if Source 6 is selected at octagon. | |
| 7 | Source 7 intensity | TBC | Report this value if Source 7 is selected at octagon. | |
| 8 | Source 8 intensity | TBC | Report this value if Source 8 is selected at octagon. |
Data taken with cal unit closed up June 7, 2022.
Wavelengths selected based on central band pass of the two detectors.
Dark was taken with the Solar calibrator unplugged and the intensity monitor out of the beam and the lamps were all off.
Source | Power at 522 nm (Watts) | Power at 735 nm (Watts) |
|---|---|---|
Broad Band | 1..72e-05 | 1.303e-05 |
UNe Daily | 1.442e-05 | 1.063e-05 |
ThAr Daily | 1.214e-05 | 9.011e-06 |
ThAr Gold | 1.581e-05 | 1.153e-05 |
UNe Gold | 2.044e-05 | 1.508e-05 |
Dark | 7.116e-10 | 6.056e-10 |
Broad band on, detector at -15000 | 1.15e-9 | |
Broad band on, detector at -25000 | 3.33e-9 | |
Broad band on, detector at -35000 | 3.77e-8 |
Relevant Datasheets & Manuals
Description | File | Source | |
|---|---|---|---|
| 1 | 1830-R-GPIB Quick Start | ||
| 2 | 1830-R-GPIB Manual | ||
| 3 | Controller Computer Interface Software | ||
| 4 | Controller Firmware | ||
| 5 | 818-SL/DB Detector Manual | ||
| 6 | 818-SL-L Detector Calibration Report | Shipped with actual KPF device | |
| 7 | Lantronix UDS 2100 Quick Start Guide | https://www.lantronix.com/products/uds2100/#tab-docs-downloads | |
| 8 | Lantronix UDS 2100 User Guide |
Relevant Software
Description | Files | Notes |
|---|---|---|
Example python code from VPH measurement system at SSL. Written for a Newport 1936-C intensity meter, which perhaps uses similar code to the KPF intensity meter (Newport 1830-R-GPIB) |
Dispatcher Implementation
Keyword | Value | Type |
|---|---|---|
POW | Power measured by detector every time delay (see above) | Double - read only |
AVGPOW | Power measured by detector averaged over a number of steps specified in NAVG | Double - read only |
AVGTIME | Time stamp of last average measurement | Time in ascii format or unix timestamp in binary format - read only |
NAVG | Number of POW measurements to average to compute AVGPOW. Dispatcher requires > 1. | Integer - writable as as well readable, default set in configuration file |
AVGSTEP | Number of POW measurements used in current AVGPOW value. Goes to 0 when NAVG is reached. | Integer - read only. |
AVG | Averaging is on or off. Turns off when AVGSTEP == NAVG. | Boolean |
SERIALCONN | Connection on or off to the device | Boolean |
NEWPORT_ID | ID string returned by device. Only valid when there is a connection. | String - read only. |
NEWPORT_REV | Revision of the firmware. | String - read only. |
ATT | Attenuator on / off | Enum - 0 Off - 1 On |
BEEP | Device Beep on / off | Enum - 0 Off - 1 On |
DISPLAY | Front panel display on / off | Enum - 0 Off - 1 On |
FILTER | Averaging on the device | Enum - 1 Slow (16) - 2 Medium (4) - 3 Fast (1 or no averaging) |
LOCK | Front paneled locked remotely, on locks | Enum - 0 Off - 1 On |
RANGE | The device does automatic scaling of the output (0) or has eight preset ranges | Enum - 0 Auto - 1 2 3 4 5 6 7 8 |
UNITS | The output units of the power measurement. Can be relative (REL) to a previous value. | Enum - 1 Watts - 2 dB - 3 dBm - 4 REL |
ZERO | Use a previous value as a zero point, can be turned on or off. | Enum - 0 Off - 1 On |
WAVE | Wavelength of light used for the detector calibration, specified in nanometers. This is only actually useful if you know the wavelength of the source and it is reasonably monochromatic. | Integer - dispatcher enforces range between 400 and 1100 |
DISP#STA | Dispatcher status. | Enum and read only. If value is 4 or “Not Connected” the connection to the Vaisala or the Lantonix is not available. If value is 3 or “Connecting” the dispatcher is attempting to connect to the Vaisala through the Lantronix. |
DISP#CONN | Dispatcher connection details, contains IP address and port separated by a colon | String |
Configuration | Value | Explanation |
|---|---|---|
dipsnum | 1 | Dispatcher number |
ip | 192.168.23.178 | IP address of the Lantronix |
port | 10001 | Port that is used, 10001 means port 1 |
Lantronix serial config | 19200, 8N1, No flow control | Serial port settings, matched to Newport 1830-R setting. |
poll_time | 0.5 | Time between data requests for the measured power value. |
navg | 10 | Default starting value for NAVG. Keyword can be written. |
wave | 658 | Default starting value for the wave parameter, the value is nm. |
units | 1 | Default starting value for units, this is Watts. |
filter | 3 | Default starting value for the filter, this is the Fast value. |
display | 0 | Default starting value for the display, this is the off value. |
Calibration Intensity Measurement
Software Actions
The calibration intensity monitor measures the intensity of calibration lamps when it is in the beam. This dispatcher automates some of the configuration and writes the measured power to a keyword whose name matches the calibration source when the measurement being performed.
The measurement only occurs when the AVG value of the calibration intensity monitor is On. It also checks that the lamp is on for which ever source is selected by the octagon stage, and that the monitor is in the beam. If either state changes during a measurement, the keyword is no longer updated. Currently it does not check the calibration intensity monitor itself.
Dispatcher Implementation
Keyword | Value | Type |
|---|---|---|
MEASURING | Yes / No - Is the average power being recorded. | boolean |
INPUT | Octagon position selected, that is also the name of the keyword that the power will be recorded to. | enumerated |
<LAMP_NAME> | The last average power value recorded. | Double |
<LAMP_NAME>_TIME | The time that the last power value was recorded. | Double |
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