Difference between revisions of "Row-specific SQ2 feedback (fast switching)"
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= Bias-card-driven SQ2FB = | = Bias-card-driven SQ2FB = | ||
| + | |||
== Prior to Rev. F == | == Prior to Rev. F == | ||
Bias Cards earlier than Rev. F have a slow opamp at the output followed by 2 sets of kHz range RC filters that limit the output switching frequency to few kHz range and prevents the output from switching at the row-visit rate. Therefore, when these bias cards are used in BC2 slot, only a constant SQ2FB value (one value per array-column) can be specified. | Bias Cards earlier than Rev. F have a slow opamp at the output followed by 2 sets of kHz range RC filters that limit the output switching frequency to few kHz range and prevents the output from switching at the row-visit rate. Therefore, when these bias cards are used in BC2 slot, only a constant SQ2FB value (one value per array-column) can be specified. | ||
* Relevant mce parameters | * Relevant mce parameters | ||
| − | ** | + | **flux_fb |
== Rev. F and later == | == Rev. F and later == | ||
| Line 12: | Line 13: | ||
:fb_col0, fb_col1, ..., fb_col31 : each specify up to 41 values, loaded in order when enbl_mux is set to 1 | :fb_col0, fb_col1, ..., fb_col31 : each specify up to 41 values, loaded in order when enbl_mux is set to 1 | ||
:enbl_mux : 0 to have constant outputs, 1 to have switching ouputs | :enbl_mux : 0 to have constant outputs, 1 to have switching ouputs | ||
| − | :flux_fb : | + | :flux_fb : |
:row_len : specifies output switching rate | :row_len : specifies output switching rate | ||
;Software requirements | ;Software requirements | ||
| + | :mas/trunk : r503 or later - servo programs will automatically detect the fast bias card. | ||
| + | :mce_script/trunk: r764 or later | ||
| + | |||
| + | ;Configuration instructions | ||
| + | * When creating mce.cfg: | ||
| + | ** $hw_rev["bc"] = "revE" or greater. | ||
| + | ** $fw_rev["bc"] = 0x5000005 or greater. | ||
| + | ** $card_list should indicate a "bc2" (i.e. not a "bac") | ||
| + | ** mce_status -g should show entries for "bc2 fb_col#" and "sq2 fb_col#" as well as "bc2 flux_fb" and "sq2 fb". | ||
| + | * In experiment.cfg: | ||
| + | ** Set one of | ||
| + | *** config_fast_sq2 = 1; # enable fast-SQ2 switching (and tuning) | ||
| + | *** config_fast_sq2 = 0; # disable fast-SQ2 switching | ||
| + | ** Set | ||
| + | *** hardware_bac = 0; # bc2 is not a bac, it's a bc2. | ||
| + | |||
= Address-card-driven SQ2FB = | = Address-card-driven SQ2FB = | ||
| − | + | ||
| + | See older instructions here: [[ Fast SQ2 Feedback and TES Biasing with an Address Card ]] | ||
| + | |||
; detector bias considerations | ; detector bias considerations | ||
| Line 24: | Line 43: | ||
:v5.0.0+ | :v5.0.0+ | ||
| − | ;Software | + | ;Software requirements |
| − | : | + | :mas/trunk : r439 or later |
| − | + | :mce_script/trunk: this has worked for a while... | |
| − | + | ||
| + | ;Configuration instructions | ||
| + | * When creating mce.cfg: | ||
| + | ** $card_list must indicate a "bac" instead of a "bc2" | ||
| + | ** mce_status -g should show entries for "bac fb_col#" and "sq2 fb_col#" and no entries for "bc2" | ||
| + | * In experiment.cfg: | ||
| + | ** Set one of | ||
| + | *** config_fast_sq2 = 1; # enable fast-SQ2 switching (and tuning) | ||
| + | *** config_fast_sq2 = 0; # simulate non-fast-SQ2 bc2 by writing the same FB value for each row. | ||
| + | ** Set | ||
| + | *** hardware_bac = 1; # we are using a bac | ||
Revision as of 19:29, 22 November 2010
The SQ2-Feedback (SQ2FB) output of the MCE, controlled by a DAC can be set to either a constant value or a row-specific set of values switching at row-visit rate. The SQ2FB output is driven by the card plugged into the BC2 slot of the MCE. Either a Bias Card or an Address Card can be plugged into the BC2 slot.
Contents
Bias-card-driven SQ2FB
Prior to Rev. F
Bias Cards earlier than Rev. F have a slow opamp at the output followed by 2 sets of kHz range RC filters that limit the output switching frequency to few kHz range and prevents the output from switching at the row-visit rate. Therefore, when these bias cards are used in BC2 slot, only a constant SQ2FB value (one value per array-column) can be specified.
- Relevant mce parameters
- flux_fb
Rev. F and later
Bias Cards Rev. F and later have faster outputs and they can be switched at row-visit rate. The firmware support for switching SQ2FB values at row-visit rate is added starting revision 5.0.5.
- Relevant mce parameters
- fb_col0, fb_col1, ..., fb_col31 : each specify up to 41 values, loaded in order when enbl_mux is set to 1
- enbl_mux : 0 to have constant outputs, 1 to have switching ouputs
- flux_fb :
- row_len : specifies output switching rate
- Software requirements
- mas/trunk : r503 or later - servo programs will automatically detect the fast bias card.
- mce_script/trunk: r764 or later
- Configuration instructions
- When creating mce.cfg:
- $hw_rev["bc"] = "revE" or greater.
- $fw_rev["bc"] = 0x5000005 or greater.
- $card_list should indicate a "bc2" (i.e. not a "bac")
- mce_status -g should show entries for "bc2 fb_col#" and "sq2 fb_col#" as well as "bc2 flux_fb" and "sq2 fb".
- In experiment.cfg:
- Set one of
- config_fast_sq2 = 1; # enable fast-SQ2 switching (and tuning)
- config_fast_sq2 = 0; # disable fast-SQ2 switching
- Set
- hardware_bac = 0; # bc2 is not a bac, it's a bc2.
- Set one of
Address-card-driven SQ2FB
See older instructions here: Fast SQ2 Feedback and TES Biasing with an Address Card
- detector bias considerations
- Firmware requirement
- v5.0.0+
- Software requirements
- mas/trunk : r439 or later
- mce_script/trunk: this has worked for a while...
- Configuration instructions
- When creating mce.cfg:
- $card_list must indicate a "bac" instead of a "bc2"
- mce_status -g should show entries for "bac fb_col#" and "sq2 fb_col#" and no entries for "bc2"
- In experiment.cfg:
- Set one of
- config_fast_sq2 = 1; # enable fast-SQ2 switching (and tuning)
- config_fast_sq2 = 0; # simulate non-fast-SQ2 bc2 by writing the same FB value for each row.
- Set
- hardware_bac = 1; # we are using a bac
- Set one of
