This is the last index code read from the Precise absolute encoder index track. For the Precise encoder, the index track contains embedded coded values. As an axis travels, the index codes are continuously read and decoded by the FPGA. When an index code is validated, the encoder counter value that corresponds to the index code is also latched.

Typically an index code is a 32-bit value, each bit spanning over 8 encoder counts. Depending on the direction of travel, the latched encoder counter for the same index code will be different. The difference is dependent on the index code design and FPGA decoding method. Currently, the default value for both the rotary encoder and linear encoder offset is 249 counts. This value must be set into DataID 10240.

During factory calibration, DataIDs 16241 and 16242 are determined, which correlates an axis position to an absolute encoder position. So, during the run-time homing process, an axis only needs to travel at most 512 (2* 32 * 8) counts to detect an index code, and then derive the calibration adjustment.

Raw encoder counter value latched that corresponds to the index pattern presented in DataId 12240.  This is the value directly read from the FPGA.  To retrieve the latched encoder counter that corresponds to the "Encoder position, ecnt" (DataID 12202), please access the "Motor position at index, mcnt" (DataID 12220).

Flag that shows the direction of travel when the last valid index code (DataID 12240) and its associated encoder position (DataID 12241) were latched. This value can be +/- 1.

Actual encoder index position adjustment applied during the run-time.