Chapter 7 Motion Control ASDA-M
7-42
Revision December, 2014
7.10.2
Function Description of COMPARE (Data Compare)
The concept of COMPARE is to compare the instant position of motion axis with the
value which is saved in data array. Then output DO3 after the COMPARE condition is
established for motion control. Since COMPARE is finished by hardware, there is no
problem of software delay. It also can accurately compare the high-speed motion axis.
The COMPARE features provided by this servo drive is as follows.
COMPARE Features
Pulse Source
Main Encoder of the Motor
Auxiliary Encoder (linear scale)
Pulse
Command
CAP Axis (set by CAPTURE). When selecting this axis,
CAP source cannot be changed.
The selected axis is displayed in P5-57. Before compare, the
default value can be written in.
Output signal
Output by DO3 and the response time is 5 usec.
Note: DO3 directly connects to COMPARE hardware, thus,
regardless the setting value of P2-20 (DO Code), the
function can work. When using COMPARE, in order to
avoid DO error, the system will force to disable DO
function, which means the setting will be P2-20 = 0x0100
automatically. Since the value is not written into
EEPROM, P2-20 will return to the default value after
re-power on.
Output Method
Pulse output can select contact A/B.
It is capable to continuously output more than one point.
It can set the pulse output time.
Data storage position
Data array. The start address is set by P5-56.
Compare number
It is set via P5-58 and will not exceed the limit of data
array.
Compare format
32-bit (It has positive and negative.)
Compare condition
It will be triggered when the source of compare axis pass
through the compare value.
Auxiliary selection
Cycle mode: When comparing to the last point, it
automatically returns to the first point and starts to
compare.
When the last compare is completed, the CAPTURE
function is activated automatically.
Note
If P5-58 is set to 0, set the value of P5-59 X, Bit0 to1 will
be unable to compare. Set the value of P5-59 X, Bit0 to 0.