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cms-gem-daq-project / gem-plotting-tools

Repository for GEM commissioning plotting tools
GNU General Public License v3.0
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Bug Report: Nominal DAC Values for DAC Scan Analysis Incorrect #203

Closed bdorney closed 5 years ago

bdorney commented 5 years ago

Brief summary of issue

Turns out some of the nominal values reported here:

https://github.com/cms-gem-daq-project/gem-plotting-tools/blob/1fdf018d8f965383a05955c93d9422f9beb383f9/utils/anaInfo.py#L17-L34

Does not match the values reported in Tables 12 & 13 of the VFAT3 Manual V2.2.

Specific Concern for CFG_HYST

In a private communication the VFAT3 team stated also that the CFG_HYST register should be kept at a value below 0xA. We should add a constraint on this register.

Types of issue

Expected Behavior

The DAC's below need to have their nominal values updated.

Additionally we should set a constraint on the CFG_HYST register to provide values always below 0xA.

Current Behavior

Specifically the following DAC's do not match the value looked in VFAT3 manual:

Register Val in GEM SW Val in VFAT3 Man.
CFG_BIAS_PRE_I_BIT 150 uA 30 uA
CFG_BIAS_PRE_I_BLCC 25 nA 2.5 uA
CFG_BIAS_PRE_I_BSF 26 uA 6.5 uA
CFG_BIAS_SD_I_BSF 30 uA 7.5 uA
CFG_HYST 100 nA 500 nA
CFG_THR_ZCC_DAC 5.5 mV 22 mV

Context (for feature requests)

Our DAC scan analysis is not assigning the correct DAC value to the above registers. We are not using the chip correctly.

Your Environment

bdorney commented 5 years ago

I did a double check of the scaling factors, e.g.:

https://github.com/cms-gem-daq-project/gem-plotting-tools/blob/1fdf018d8f965383a05955c93d9422f9beb383f9/utils/anaInfo.py#L36-L54

And they are all correct.

AndrewLevin commented 5 years ago

The values that are there now are the "Nominal Current" in Table 9 and the "Nominal Voltage" in Table 10.

bdorney commented 5 years ago

The values that are there now are the "Nominal Current" in Table 9 and the "Nominal Voltage" in Table 10.

Looks like we'll have to ask the VFAT3 team what the difference is...

bdorney commented 5 years ago

VFAT3 team reports that Tables 9 and 10 should be used for configuring and data taking.

Closing as "NotABugWontFix"