4.6 Absolute Encoders4-334 Operation4.6 Absolute EncodersIf using an absolute encoder, a system to detect the absolute position can be designed for use with the hostcontroller. As a result, an operation can be performed without a zero point return operation immediately afterthe power is turned ON.A battery case is required to save position data in the absolute encoder.The battery is attached to the battery case of the encoder cable.If an encoder cable with a battery case is not used, install a battery to the host controller.Set Pn002.2 to 0 (factory setting) to use the absolute encoder.A battery is not required when using the absolute encoder as an incremental encoder.PROHIBITED• Do not install batteries in both the host controller and battery case. It is dangerous because that sets up aloop circuit between the batteries.Parameter Meaning WhenEnabled ClassificationPn002n.0[Factory setting] Uses the absolute encoder as an absolute encoder. After restart Setupn.1 Uses the absolute encoder as an incremental encoder.The rotational serial data output range for a large-capacity Σ-V-series absolute positiondetecting system is different from the range for previous Σ-series systems. As a result,the infinite-length positioning system of the Σ servo drives must be changed for use withΣ-V large-capacity servo drives. Be sure to make the following system modifications.∗ This is the resolution for a motor capacity of 22 kW or higher.Series (Models)AbsoluteEncoderResolution*Output Rangeof RotationalSerial DataAction when Limit Is ExceededΣ Series(SGDB)12-bit15-bit-99999 to+ 99999• When the upper limit (+99999) isexceeded in the forward direction, the rota-tional serial data will be 0.• When the lower limit (-99999) is exceededin the reverse direction, the rotationalserial data will be 0.Σ-II Series(SGDM/SGDH)or large-capacityΣ-V Series(SGDV)17-bit20-bit-32768 to+ 32767• When the upper limit (+32767) isexceeded in the forward direction, the rota-tional serial data will be -32768.• When the lower limit (-32768) is exceededin the reverse direction, the rotationalserial data will be +32767.Note: If you change the multiturn limit set-ting (Pn205), the operation will be differentfor both forward and reverse rotation. (Referto 4.6.6 Multiturn Limit Setting.)
