Archon CCD Controllers
- Steve Gibson
Table of Contents:
Introduction
KPF contains two CCDs, one for the Green channel and one for the Red channel. Both CCDs are STA 4850 devices (30 um thick), with only their bandpass-optimized coatings differing between them. Each CCD is controlled by an STA Archon AC controller. These are the ‘all-in-one’ version of the Archons which have the integral power supply.
The KPF Archons sit directly above the KPF vacuum chamber, on top of the roof of the spectrometer thermal enclosure. This choice was made to minimize the cable length between CCD and controller, as longer cables can increase the read noise in the system. Within KPF, the cable between controller and CCD is 2m long.
The Archons are controlled by KPF software over ethernet. Fiber-based ethernet was chosen over copper ethernet to better isolate the Archons from noise sources. The fiber cable is a duplex LC-terminated cable with an SFP transceiver at each end (within the Archon and the KPF Main Switch).
Exposures are initiated and ended via TTL trigger signals generated by the Shutters and Timing Galil.
The Archons also contain STA HeaterX modules which control several temperatures within the CCD thermal chain (see CCD Thermal Control System for more details).
Relevant Devices
Description | Qty | Source | Part Number |
|---|---|---|---|
Green Archon | 1 | STA | Archons are custom-built for the desired internal board options. See Initial Configuration section below to see the options chosen for the KPF Archons. |
Red Archon | 1 | STA |
Initial Configuration
Quotes for the two KPF Archons are included here to show their initial configurations. Red arrows highlight the difference between them (one has an extra 4 channel AD board). The green arrow shows that both where shipped with the XV Bias board, which is known to fail. This board is only needed when using the Archons with thicker, 100-um devices. Since both KPF CCDs are 30-um thick these boards are not needed.
In May 2023 the Green Archon XV Bias board failed and was removed. There are plans to remove the Red XV Bias board as well.
Relevant Functional Block Diagram
Cable Details
Note the cabling for the Green and Red Archons is identical. Cable lengths and details are included here:
HeaterX Details - Telemetry and Control
Starting list of Archon telemetry, for the temperature sensors and heaters only.
The “Reply” column is what is reported back from an Archon-native ‘STATUS’ command being passed through the COO Detector Server (camerad).
See “Native Controller Commands” Section of COO Detector Server manual. The manual also has this related blurb:
The table below gives the replies that pertain to the temperature sensors and heaters parameters.
Steve Kaye has said that our KPF HeaterX cards are at locations ‘01’ and ‘07’. I presume then what is given as ‘m' in the replies is either ‘01’ or ‘07’ or ‘1’ or '7’.
Note: It seems the Archon reports temperatures in Kelvin. Please have the dispatcher convert them to degrees C before writing values to keywords (so that they match the rest of our temperatures).
HeaterX Card |
Reply | Reply Type Code |
Reply Type |
Comment |
KPF Location |
KTL Service |
KTL Keyword |
HeaterX 1
m = ‘1’ | STATUS:MODm/TEMPA | f | Float | Heater(X) only: Floating point temperature sensor A reading in K | Base Cold Finger |
kpfgreen | CF_BASE_T |
STATUS:MODm/TEMPB | f | Float | Heater(X) only: Floating point temperature sensor B reading in K | Tip Cold Finger | CF_TIP_T | ||
STATUS:MODm/TEMPC | f | Float | HeaterX only: Floating point temperature sensor C reading in K | Base Cold Finger (2-Wire) | CF_BASE_2WT | ||
STATUS:MODm/HEATERAOUTPUT | f | Float | Heater only: Floating point heater A output in V | Base Cold Finger Htr | CF_BASE_HTR_V | ||
STATUS:MODm/HEATERBOUTPUT | f | Float | Heater only: Floating point heater B output in V | Tip Cold Finger Htr | CF_TIP_HTR_V | ||
STATUS:MODm/HEATERAP | d | Signed Integer | Heater only: Heater A P term contribution to PID loop (signed integer) |
N/A | CF_BASE_HTR_P | ||
STATUS:MODm/HEATERAI | d | Signed Integer | Heater only: Heater A I term contribution to PID loop (signed integer) | CF_BASE_HTR_I | |||
STATUS:MODm/HEATERAD | d | Signed Integer | Heater only: Heater A D term contribution to PID loop (signed integer) | CF_BASE_HTR_D | |||
STATUS:MODm/HEATERBP | d | Signed Integer | Heater only: Heater B P term contribution to PID loop (signed integer) | CF_TIP_HTR_P | |||
STATUS:MODm/HEATERBI | d | Signed Integer | Heater only: Heater B I term contribution to PID loop (signed integer) | CF_TIP_HTR_I | |||
STATUS:MODm/HEATERBD | d | Signed Integer | Heater only: Heater B D term contribution to PID loop (signed integer) | CF_TIP_HTR_D | |||
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HeaterX Card |
Reply | Reply Type Code |
Reply Type |
Comment |
KPF Location |
KTL Service |
KTL Keyword |
HeaterX 7
m = '7' | STATUS:MODm/TEMPA | f | Float | Heater(X) only: Floating point temperature sensor A reading in K | STA Detector |
kpfgreen | STA_CCD_T |
STATUS:MODm/TEMPB | f | Float | Heater(X) only: Floating point temperature sensor B reading in K | SSL Detector | KPF_CCD_T | ||
STATUS:MODm/TEMPC | f | Float | HeaterX only: Floating point temperature sensor C reading in K | Cryo Body | CRYOBODY_T | ||
STATUS:MODm/HEATERAOUTPUT | f | Float | Heater only: Floating point heater A output in V | Detector Htr | STA_CCD_HTR_V | ||
STATUS:MODm/HEATERBOUTPUT | f | Float | Heater only: Floating point heater B output in V | Cryo Body Htr | CRYOBODY_HTR_V | ||
STATUS:MODm/HEATERAP | d | Signed Integer | Heater only: Heater A P term contribution to PID loop (signed integer) |
N/A | CCD_HTR_P | ||
STATUS:MODm/HEATERAI | d | Signed Integer | Heater only: Heater A I term contribution to PID loop (signed integer) | CCD_HTR_I | |||
STATUS:MODm/HEATERAD | d | Signed Integer | Heater only: Heater A D term contribution to PID loop (signed integer) | CCD_HTR_D | |||
STATUS:MODm/HEATERBP | d | Signed Integer | Heater only: Heater B P term contribution to PID loop (signed integer) | CRYOBODY_HTR_P | |||
STATUS:MODm/HEATERBI | d | Signed Integer | Heater only: Heater B I term contribution to PID loop (signed integer) | CRYOBODY_HTR_I | |||
STATUS:MODm/HEATERBD | d | Signed Integer | Heater only: Heater B D term contribution to PID loop (signed integer) | CRYOBODY_HTR_D |
Each module/board within the Archon has an integrated temperature sensor. These temperatures are available through the STATUS command as shown in this table:
Reply | Reply Type Code | Reply Type | Comment | Board Name | KTL Service | KTL Keyword |
|---|---|---|---|---|---|---|
| f |
Float | Floating point module m temperature in C | HeaterX |
kpfgreen | BRD1_HTRX_T |
| f | Floating point module m temperature in C | XV Bias | BRD2_XVBIAS_T | ||
| f | Floating point module m temperature in C | LVDS | BRD3_LVDS_T | ||
| f | Floating point module m temperature in C | Driver | BRD4_DRVR_T | ||
| f | Floating point module m temperature in C | AD | BRD5_AD_T | ||
| f | Floating point module m temperature in C | HeaterX | BRD7_HTRX_T | ||
| f | Floating point module m temperature in C | HVxBias | BRD9_HVXBIAS_T | ||
| f | Floating point module m temperature in C | Driver | BRD10_DRVR_T | ||
| f | Floating point module m temperature in C | Driver | BRD11_DRVR_T | ||
| f | Floating point module m temperature in C | LVxBias | BRD12_LVXBIAS_T |
Relevant Datasheets & Manuals
Description | File | Source | |
|---|---|---|---|
| 1 | Archon Manual | 
|
Maintenance Procedures
Description | File | Source | |
|---|---|---|---|
| 1 | Instructions to remove the troublesome XV Bias board (which is not required for KPF) |  | Greg Bredthauer at STA |