Difference between revisions of "Bias Card RevD to RevE changes"
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(Created page with '; Low-noise Bias lines : Low noise bias lines are meant to be used as TES bias lines. Bias Card Rev. E provides 12 independent bipolar low-noise bias lines (LN_BIAS) in addition …') |
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: Vah is used in Rev. D cards to provide the reference voltage for the DACs. | : Vah is used in Rev. D cards to provide the reference voltage for the DACs. | ||
| − | ; | + | ; Software considerations |
| − | : | + | : To make the 12 bias lines commandable, set $hw_rev["bc"] = "revE" (or greater) in [[ mce.cfg | mce.cin ]]. This will add a op_xor entry in mce.cfg file to make a 2's complement interpretation of values entered so that ''wb bc2 bias 0'' is aligned with 0V and ''wb bc2 bias 32767'' with +5V. |
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: in [[experiment.cfg]], set hardware_fast_sq2 accordingly | : in [[experiment.cfg]], set hardware_fast_sq2 accordingly | ||
; Firmware consideration | ; Firmware consideration | ||
: The FPGA pins assigned to control lines for ln_bias DACs are not compatible with Rev. D nor Rev. F cards. Therefore, special RevE firmware is needed to be able to excercise ln_bias DACs (bias command). | : The FPGA pins assigned to control lines for ln_bias DACs are not compatible with Rev. D nor Rev. F cards. Therefore, special RevE firmware is needed to be able to excercise ln_bias DACs (bias command). | ||
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| + | [[Category:Bias Card]] | ||
Latest revision as of 14:58, 31 August 2016
- Low-noise Bias lines
- Low noise bias lines are meant to be used as TES bias lines. Bias Card Rev. E provides 12 independent bipolar low-noise bias lines (LN_BIAS) in addition to the 32 regular biases. The 12th low-noise bias is what was called det_bias in Rev. D cards. Rev. D cards shared a DAC between two outputs called Heater and det_bias.
- Note that the low-noise bias line in Rev. D was unipolar with 0 to +5V range, while low-noise bias lines in Rev. F are bipolar from -5V to +5V. At powerup, the output voltage is 0V, equivalent to an input pattern of 0x8000.
- 10V supply
- Vah or 10V supply is not used by Rev. F cards anymore. The reference voltage for the DACs is generated from pVa or 6.2V supply instead.
- Vah is used in Rev. D cards to provide the reference voltage for the DACs.
- Software considerations
- To make the 12 bias lines commandable, set $hw_rev["bc"] = "revE" (or greater) in mce.cin . This will add a op_xor entry in mce.cfg file to make a 2's complement interpretation of values entered so that wb bc2 bias 0 is aligned with 0V and wb bc2 bias 32767 with +5V.
- in experiment.cfg, set hardware_fast_sq2 accordingly
- Firmware consideration
- The FPGA pins assigned to control lines for ln_bias DACs are not compatible with Rev. D nor Rev. F cards. Therefore, special RevE firmware is needed to be able to excercise ln_bias DACs (bias command).
