1.4.4 Tentative Absolute Coordinate Setting
In a full–closed system with a built–in absolute position detector (serial pulse coder) and incremental linear scale, a coordinate system is set up, using absolute position data received from the built–in absolute position detector when the power is switched on. After this, position control is carried out using the linear scale incremental data. Because the machine position obtained immediately after the power is switched on is tentative, obtaining the accurate machine position requires making a manual
reference position return.
Even before a reference position return is made, using this function enables a stroke limit, although the machine position obtained when the power is switched on is approximate.
Note that this function is not intended to use an incremental linear scale as an absolute position detector.
This function is an option.
(attached)
Fig. 1.4.4 System using tentative absolute coordinate system setting
Parameter
#7 #6 #5 #4 #3 #2 #1 #0
1801 INA
[Data type] Bit
1801#3 INA Specifies whether to perform absolute position communication for re–setting up the machine position at a reset after a servo alarm other than alarm 413 (LSI overflow), 416, 445, 446, or 447 (broken–wire alarm) occurs in a system that uses an absolute position detector, as follows:
0 : To perform.
1 : Not to perform.
NOTE
1 If INA = 0 in a system that uses tentative absolute coordinate system setting, the machine position is approximate after a servo alarm other than 413, 416, 445, 446, or 447 is reset, because it has been re–set up using data received from the built–in absolute position coder.
2 When a reset is performed after a servo alarm 413, 416, 445, 446, or 447 occurs, absolute position communication for re–setting up the machine position always takes place.
#7 #6 #5 #4 #3 #2 #1 #0
1815 APCx OPTx
[Data type] Bit axis
#1 OPTx Specifies whether to use a separate position detector, as follows:
0 : Not to use.
1 : To use.
#5 APCx Specifies whether to use a absolute position detector, as follows:
0 : Not to use.
1 : To use.
NOTE
1 When using tentative absolute coordinate system setting, set both OPTx and APCx to 1.
2After setting any of these parameters, turn the power off then on again so that the setting will take effect.
1874 = Flexible feed gear numerator for built–in position detector
1875 = Flexible feed gear denominator for built–in position detector
[Data type] Word axis
[Valid data range] 1 to 32,767
Specifies a flexible feed gear for a built–in position detector for each axis when using tentative coordinate system setting, according to the following expression:
(NO.1874/NO.1875)=(Number of position feedback pulses per motor revolution)/(1,000,000)
NOTE
1 These parameters can be used also in a system that uses the Inductosyn.
2 After setting any of these parameters, turn the power off then on again so that the setting will take effect.
#7 #6 #5 #4 #3 #2 #1 #0
2011 XIAx
[Data type] Bit axis
#7 IN Specifies whether to enable tentative absolute coordinate system setting, as follows:
0 : To disable.
1 : To enable.
NOTE
Using tentative absolute coordinate system setting requires setting bit 1 (OPTx) of parameter No. 1815, bit 5 (APCx) of parameter No. 1815, parameter No. 1874, and parameter No. 1875.