HarmonicDrive H A - 800A, Руководство пользователя

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4-2 17-bit absolute encoder
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4-2 17-bit absolute encoder
If AL81 (system failure), AL82 (single rotation data error) or AL83 (multi
revolution data error) occurs due to a loss of absolute position or error, be sure
to reset the origin. Failure to do so may result in unexpected operations.
Features
The SHA series (excluding SHA20) is equipped with a multi revolution-type 17-bit magnetic absolute
encoder.
The SHA20 and FHA-Cmini series is equipped with a multi revolution-type 17-bit optical absolute
encoder. (Multi revolution detection is magnetic.)
It consists of a detector (17 bits/revolution) for detecting the position after one motor shaft revolution
and a cumulative counter (16 bits) for detecting the number of motor revolutions.
This encoder constantly detects the absolute machine position and stores it by means of the backup
battery, regardless of whether the power supply for driver or external controller is turned ON/OFF.
Accordingly, once the origin is detected when the machine is installed, originating is not required after
subsequent power ON operations. This facilitates the recovery operation after a power failure or
breakdown.
The SHA-CG output shaft single revolution absolute model (SHA-CG-S) assumes a machine that only
moves the index table in one direction. When the machine continues to rotate in just one direction, the
absolute encoder eventually exceeds the number of revolutions that can be detected with
multi-revolution detection and it becomes impossible to manage position information accurately.
Therefore, each time the output shaft turns through single revolution, the cumulative multi revolution
counter is cleared to 0 to achieve the output shaft single revolution absolute function. This is how
position information is accurately managed when the shaft continuously turns in just one direction.
With the 17-bit absolute encoder, the single revolution absolute position detector and the revolution
detection/cumulative counter are both made dual-redundant. Two identical data items are constantly
compared to ensure highly reliable design permitting self-detection of encoder errors should they
occur.
A backup capacitor is also provided in the encoder. (Internal backup. Take note that the retention time
is short.)
The 17-bit encoder incremental model does not perform multi revolution detection and do not require a
backup battery. Otherwise it is the same as a 17-bit absolute encoder.
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The backup time is 30 minutes when a new capacitor has been charged for at
least 3 hours by supplying power to the actuator. This backup time becomes
shorter if the power is supplied for a shorter period or the capacitor deteriorates
over time.
CAUTION