Axis Monitor Devices - Mitsubishi Electric MELSEC Q Series Programming Manual

3 POSITIONING DEDICATED SIGNALS

3.2.1 Axis monitor devices

The monitoring data area is used by the Motion CPU to store data such as the feed
current value during positioning control, the real current value and the deviation
counter value.
It can be used to check the positioning control state using the Motion SFC program.
The user cannot write data to the monitoring data area.
Refer to "APPENDIX 4 Processing Times of the Motion CPU" for the delay time
between a positioning device (input, internal relay and special relay) turning on/off and
storage of data in the monitor data area.
(1) Feed current value storage register (D0+20n, D1+20n)
(a) This register stores the target address output to the servo amplifier on the
basis of the positioning address/travel value specified with the servo
program.
1) A part for the amount of the travel value from "0" after starting is stored
in the fixed-pitch feed control.
2) The feed current value storage register (D0+20n, D1+20n) during
speed-position switching control and speed control is as follows.
a) When using Q173DSCPU/Q172DSCPU
• In the speed-position switching control and speed control ( ), the
address at the start depends on the state of feed current value
update command (M3212+20n) as shown below.
• M3212+20n: OFF ... Resets the feed current value to "0" at the start.
• M3212+20n: ON ... Not reset the feed current value at the start.
• "0" is stored during speed control ( ).
b) When using Q173DCPU(-S1)/Q172DCPU(-S1)
• In the speed-position switching control, the address at the start
depends on the state of feed current value update command
(M3212+20n) as shown below.
• M3212+20n: OFF ... Resets the feed current value to "0" at the start.
• M3212+20n: ON ... Not reset the feed current value at the start.
• "0" is stored during speed control ( ) and speed control ( ).
(b) The stroke range check is performed on this feed current value data.
(2) Real current value storage register (D2+20n, D3+20n)
(a) This device stores the converted value (in an axis control unit) of the
feedback position of the motor encoder (in pulse unit).
(b) The "feed current value" is equal to the "real current value" in the stopped
state.
(3) Deviation counter value storage register (D4+20n, D5+20n)
This register stores the droop pulses read from the servo amplifier.
............................. Monitor device
............................. Monitor device
............................. Monitor device
3 - 49