MCA-3K Data Server Reference

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Overview

MCA-3K Data Structure: arm_ctrl

Summary

The arm_cal data structure contains the data used for gain stabilization.

Data structure

For arm_cal there are 64 'register' and 10 named 'fields' data in use. All register data are 32-bit floats (float32).

The fields led_ov, led_dg, led_lut are lists of 2 to 20 float32 values. The first list entry corresponds to the lowest temperature (lut_tmin) of the lookup table.

When using the lookup tables for gain stabilization, the ARM processor uses linear interpolation within the table and linear extrapolation for temperatures outside the table's temperature range.

arm_cal registers and fields
Register number and field nameDescription
0: lut_lenNumber of entries in the LUT; default is 19, 2..19 are allowed
1: lut_tminMinimum temperature in the lookup table; Typically -30°C
2: lut_dtTemperature step size in the lookup table; Typically 5°C
[3:22]: lut_ovChange of operating voltage vs temperature
[23:42]: lut_dgChange of digital gain vs temperature
[43:62]: lut_ledChange of LED target vs temperature
63: lut_modeint(lut_mode)&0x1 → lock bit, set to 1 to prevent the user from reading the arm_cal data from the MCA.
The arm_cal registers and fields.

The MCA-3K ships with a factory-provided lookup table. Its content can be loaded into flash memory and RAM when reading arm_cal with memory type "reset".

Factory reset arm_cal registers and fields
Register number and field nameDescription
0: lut_len20
1: lut_tmin-30°C
2: lut_dt5°C
[3:23]: lut_ovChange of operating voltage vs temperature
[23:43]: – Change of digital gain vs temperature
[43:63]: – Change of led_target vs temperature
63: lut_mode1: lock bit, set to 1 to prevent data read back.
The factory reset arm_cal registers and fields. Index ranges [a:b] include the first and last index.