Resetting The Absolute Encoder; Precautions On Resetting; Preparations - YASKAWA SGD7S Product Manual

5.16 Resetting the Absolute Encoder

5.16.1 Precautions on Resetting

5.16

Resetting the Absolute Encoder

In a system that uses an absolute encoder, the multiturn data must be reset at startup. An
alarm related to the absolute encoder (A.810 or A.820) will occur when the absolute encoder
must be reset, such as when the power supply is turned ON.
When you reset the absolute encoder, the multiturn data is reset and any alarms related to the
absolute encoder are cleared.
Reset the absolute encoder in the following cases.
• When starting the system for the first time
• When an A.810 alarm (Encoder Backup Alarm) occurs
• When an A.820 alarm (Encoder Checksum Alarm) occurs
• When you want to reset the multiturn data in the absolute encoder
Information

5.16.1 Precautions on Resetting

• You cannot use the ALM_CLR (Clear Alarm) command from the SERVOPACK to clear the
A.810 alarm (Encoder Backup Alarm) or the A.820 alarm (Encoder Checksum Alarm). Always
use the operation to reset the absolute encoder to clear these alarms.
• If an A.8 alarm (Internal Encoder Monitoring Alarm) occurs, turn OFF the power supply to
reset the alarm.

5.16.2 Preparations

Always check the following before you reset an absolute encoder.
• The parameters must not be write prohibited.
• The servo must be OFF.
5-46
 The multiturn data will be reset to a value between -2 and +2 rotations when the absolute
encoder is reset. The reference position of the machine system will change. Adjust the refer-
ence position in the host controller to the position that results from resetting the absolute
encoder.
If the machine is started without adjusting the position in the host controller, unexpected
operation may cause personal injury or damage to the machine.
The multiturn data will always be zero in the following cases. It is never necessary to reset the
absolute encoder in these cases.
• When you use a single-turn absolute encoder
• When the encoder is set to be used as a single-turn absolute encoder (Pn002 = n.2)
Also, an alarm related to the absolute encoder (A.810 or A.820) will not occur.
CAUTION