Siemens SIMATIC ET 200SP Manual page 77

Cam control operating mode
6.2 Parameters/address space
The value status of the encoder module affects the value status of the DQ4HS module. If the
value status of the encoder module is invalid, the value status of the DQ4HS module is set to
0.
For encoder modules that do not provide a direction in the encoder data, it must be kept in
mind that only 2 valid different encoder values have to be available in the cam control before
the internal direction detection can evaluate the encoder value and the associated
configured cam. With the first valid encoder value, INP_OK = 1 is set, and with the second
valid value, SYNC = 1 is additionally set.
Hysteresis
With the help of a hysteresis, fluctuations (minimal direction reversal in the encoder value)
that affect the encoder value can be compensated.
The hysteresis setting must satisfy the following conditions:
● Hysteresis < ABS ((maximum encoder value - minimum encoder value) / 4)
● Hysteresis < Cam
Axis reference position
With the help of the axis reference position, the encoder value can be adapted or corrected,
e.g. for taking the zero position of the sensor into account. The axis reference position is
subtracted from the encoder value before further processing of the encoder value.
Encoder value minimum/maximum
● "Minimum encoder value" is the low value of the valid encoder range. When "Modulo" is
activated, this value is the start value for the modulo operation.
● "Maximum encoder value" is the high value of the valid encoder range. When "Modulo" is
activated, this value is used for calculating the length for the modulo operation.
The difference of "Maximum encoder value" and "Minimum encoder value" must be at least
2.
When "Modulo" is deactivated, a check is made to determine whether the encoder value is
less than "Minimum encoder value" and greater than "Maximum encoder value".
When "Modulo" is activated, the result of "Maximum encoder value" - "Maximum encoder
value" must not exceed the value 2,147,483,646.
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end position - Cam start position [i = 0 to 15]
i i
Digital output module DQ 4x24VDC/2A HS (6ES7132-6BD20-0DA0)
Manual, 06/2018, A5E32855695-AC