Input Description

EN   BOOL \   (enable)

In order to enable the Function Block processing, input EN has to be continuously set to TRUE. The block is not processed if input EN = FALSE.

While input is set to TRUE, the inputs are continuously checked for validity and plausibility. If this is not the case, processing is aborted and corresponding error is displayed at output ERR/ERNO.

CNT_NUM   WORD \   (counter \ number)

Indicates which counter is going to be used:

If CNT_NUM = 0, the counter 0 will be used.

If CNT_NUM = 1, the counter 1 will be used.

EN_CNT   BOOL \   (enable \ counter)

IF EN_CNT = TRUE, communications process with SSI encoder is enabled. If EN_CNT = FALSE, communications process with SSI encoder is not enabled.

CALC_OFFSET   BOOL \   (calculated \ offset)

This input is used to calibrate the positioning sensor. When rising edge is detected at CALC_OFFSET, Function Block proceeds as follow:

OFFSET_VALUE = POS_CALC ACT_CNT,

where ACT_CNT is the read value directly from encoder (internal variable).

Once the system is calibrated, this value remains constant during the normal working of the system. This  value should be check to do a correct calibration after maintenance operations.

POS_CALC   REAL \   (position_calculted)

It is the right position of our tracker and it is used to calibrate the system. This value must be obtained by using high accuracy tools (not assembled in the tracker) or by using a sun sensor to determine if tracker is right focused.

Format: Degrees.

SSI_RESOLUTION   BYTE \   (SSI \ RESOLUTION)

The resolution of the encoder device setting by number of bits. Min. 8 bits, max. 32 bits.

MEASURING_STEP   REAL \   (measuring \ step)

The resolution of the encoder device (see technical data from manufacturer).

Format: Degrees.

CNT_IN   WORD \   (counter \ input)

First input data of counter input. The use of an ADR operator is not needed.

Example (for counter 0):

In Control Builder Plus V2.0 and above:

CNT_OUT   WORD \   (counter \ output)

First output data of counter output. The use of an ADR operator is not needed.

Example (for counter 0):

In Control Builder Plus V2.0 and above:

OFFSET_VALUE   REAL \   (offset \ value)

Value added to ACT_CNT (internal variable) to obtain a calibrating process.

POS_ACT = ACT_CNT + OFFSET_VALUE,

where ACT_CNT is the directly read value from encoder (internal variable).

Format: Degrees.

POS_ACT   REAL \   (position \ actual)

The current position (actual position) can be retrieved at any time using the output POS_ACT of the Function Block.

Format: Degrees.