Siemens SINUMERIK 840D sl Function Manual page 88

Basics regarding the safety functions integrated in the system/drive
6.4 Actual value conditioning
DRIVE-CLiQ encoder
If a DRIVE-CLiQ encoder is connected for the NCK monitoring channel (drive parameter r9527
= 2 or 3), in addition to the parameter field r0979, additional drive parameters that define the
redundant coarse position value in more detail must be read-out. When booting, these
parameters are directly read-out of the encoder and saved in the NCK machine data.
The additional parameters for DRIVE-CLiQ encoders are listed in the following table:
Drive parameters
r0469 Resolution measuring steps for linear absolute encod‐
ers (DRIVE-CLiQ linear encoder)
r0470 Valid bits for the redundant coarse position value
(DRIVE-CLiQ encoder, binary)
r0471 Fine resolution of the redundant coarse position value
(DRIVE-CLiQ encoder, binary)
r0472 Relevant bits of the redundant coarse position value
(DRIVE-CLiQ encoder, binary)
r0473 Non-safety-related measuring steps position value
POS2 (DRIVE-CLiQ linear encoder)
r0474 Configuration of the redundant coarse position value
Bit 0: Count direction, up/down
Bit 1: CRC 16: LSB/MSB first
Bit 2: MSB/LSB - justified
Bit 4: Binary comparison not possible
r0475 = Safety MSB of the redundant coarse position value
r0470 - r0471 (DRIVE-CLiQ encoder, binary)
The difference between DRIVE-CLiQ encoder, binary or linear, is derived from drive parameter
r0474, bit 4:
● r0474.4 = 0: DRIVE-CLiQ encoder, binary
● r0474.4 = 1: DRIVE-CLiQ encoder, linear or not binary
The relevant drive parameters are evaluated, depending on the DRIVE-CLiQ prototype (binary
or linear). Different algorithms are used to compare the redundant coarse position value with
the actual value. All of the NCK machine data listed in the table above are incorporated in the
checksum via the axis-specific NCK machine data in order to identify any inadvertent changes.
In so doing, machine data:
● $MA_SAFE_ENC_NUM_BITS[0,1]
● $MA_SAFE_ENC_CONF
are incorporated in the hardware-related checksum check $MA_SAFE_ACT_CHECKSUM[1].
If one of these NCK machine data do not match the associated drive parameter, then Alarm
27035 "Axis %1 new HW component, acknowledgment and function test required" is output.
The following machine data
● $MA_SAFE_ENC_NUM_BITS[2,3]
● $MA_SAFE_ENC_MEAS_STEPS_RESOL
● $MA_SAFE_ENC_MEAS_STEPS_POS1
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Meaning NCK machine data
$MA_SAFE_ENC_MEAS_STEPS_RESOL
$MA_SAFE_ENC_NUM_BITS[0]
$MA_SAFE_ENC_NUM_BITS[1]
$MA_SAFE_ENC_NUM_BITS[2]
$MA_SAFE_ENC_MEAS_STEPS_POS1
$MA_SAFE_ENC_CONF
$MA_SAFE_ENC_NUM_BITS[3]
Function Manual, 12/2017, 6FC5397-4BP40-6BA1
Safety Integrated