Project

General

Profile

Task #13919

Fix scaling for ring pick MPS thresholds

Added by John Diamond about 4 years ago. Updated about 4 years ago.

Status:
Assigned
Priority:
Normal
Assignee:
John Diamond
Category:
MPS
Start date:
09/23/2016
Due date:
% Done:

80%

Estimated time:
8.00 h
Spent time:
10.00 h
Duration:

Description

The PXIE ring pickup MPS thresholds never made sense because they are set in ADC integrated counts. Ning has provided a method for scaling to amps -

Intensity Threshold ( P:MPRLT , P:MPRUT ):

I_THR: Register Value for thresholds.
Threshold_Setting: D80 Setting (common unit, E10?) for thresholds.
GW: Raw Gate Width Reading

Revised:
I_THR = log_base_C3( ( Threshold_Setting / ( GW * C5 ) - C4 ) / C1 ) * GW / C2

C1 = 0.3660774
C2 = 0.0003773625
C3 = 1.7
C4 = -0.268996

C5 = 4.9932073
C6 = 0

---- Note: the outside parts of this formula can be done on D80,
                Otherwise, leave D80 scaling to 1.

History

#1 Updated by John Diamond about 4 years ago

The above formula scales to E10 not Amps.

#2 Updated by John Diamond about 4 years ago

Gate Width should be the gate width as read from the digitizer in raw ADC clock ticks.

#3 Updated by John Diamond about 4 years ago

I came up with the inverse function as -

  Threshold_Setting = (C5 * GW) * (C4 + C1 * C3^( (C2 * I_THR) / GW ))

#4 Updated by John Diamond about 4 years ago

  • % Done changed from 0 to 80
Implemented support for scaling the MPS upper/lower thresholds inside the front end.
Created a CLI command for specifying scaling parameters:
vmeintMPSThresholdScaleFilterSet deviceId, scaleMethodStr, c1Str, c2Str, c3Ctr, c4Str, c5Str, c6Str
  • deviceId is the intensity device ID
  • scaleMethodStr specifies what kind of scaling should be done. The default method is "linear". For the PXIE ring pickups this parameter should be "pxie_ring_pickup".
  • c1Str .. c6Str are the scaling coefficients (these are floating-point parameters, they must be passed as strings e.g. "2.0")
    • linear: C1 * x / C2 + C3
    • pxie_ring_pickup: log_base_C3( ( x / ( GW * C5 ) - C4 ) / C1 ) * GW / C2

#5 Updated by John Diamond about 4 years ago

Add a line of output to vmeintShow to display the MPS threshold scaling information:

Intensity Devices -
        Toroid
        Device ID: 0
        ADC ID: 0, channel: 0
        Readouts: BBB disabled, raw disabled
        DAQ Source: 0
        MPS: Enabled    NOT TRIPPED
                Lower: NaN, Upper: NaN, Edge Threshold: 4096
                Threshold Scaling: log_base_C3( (x / (gate_width * C5) - C4) / C1 ) * gate_width / C2, where C1 = 0.366 C2 = 0.000377 C3 = 1.7 C4 = -0.26 C5 = 4.99 (pxie_ring_pickup)
                Pulse Direction: 0 (-)
                Pulse Width: 0 ns
                Time Check: Enabled, margin: 128 clock ticks

Also available in: Atom PDF