Omron CS1W-MCH71 Operation Manual page 149

System Parameters
Motor axis speed [Motor rev/min] =
104
The overview of the relations between the machine axis speed [command
unit/min] and motor axis rotations [r/min] can be described by the following for-
mula.
Machine axis speed [Command unit/min]
P5AA04 [Command unit/One machine rotation]
Minimum speed to avoid intermittent output:
Minimum speed command is 1 command unit/unit scan. When outputting
slower speed than this, the output will be intermittent on the waveform.
Minimum speed [Command unit/min] = 1 [Command unit/ms] × 60 [sec/min] ×
1000 [ms/sec] × unit scan time [ms]
Precision of feedback speed 1 and 2:
Precision of feedback speed 1 and 2 output to the system variable is as fol-
lows:
• Precision of feedback speed 1
Feedback speed, based on the unit [pulses/ms], is ultimately converted
into the divisions of the minimum speed mentioned above, and will be out-
put.
Therefore, the minimum speed will be the resolution of the feedback
speed 1.
Ex) When the unit cycle is 4 [ms]:
Minimum speed [command unit/min] = 1 × 60 × 1000 × 4
From the above, the feedback speed 1 will change in the unit of 240000
[command units/min].
• Precision of feedback speed 2
Precision of feedback speed [r/min] = 1 [pulses/ms] × 1000 × 60/9001h
[No. of encoder pulses/motor rotation])/unit cycle [ms]
Ex) When encoder resolution is 16 bits [10000h pulses/r] and unit cycle
is 4 [ms]:
Precision of feedback speed [r/min] = 1 × 1000 × 60/65536/4
From the above, the feedback speed 2 will change in the unit of 0.22 [r/
min].
Setting rated 1000 [r/min] when the unit is [%], it will be in the unit of 0.22/
1000 = 0.02%.
Speed indication for not causing [A94] when inputting the limit sensor
signal:
When the limit sensor signal is input to the servo driver during rotations, the
warning [A94: Data Setting Warning] may occur on NS115 due to communi-
cations delay. There is no deviation in positioning, yet the speed that causes
the alarm is to be explained in the following:
Speed that causes A94 [Command unit/min] = Speed command MAX [Pulse]/
delay in Communications cycle [ms] × gear reverse conversion [Command
unit/ pulse] × 60 [sec/min] × 1000 [ms/sec]
• Speed command MAX: In case of NS115, it is fixed at 32767[pulse].
• Delay in Communications cycle: No. of times until MC Unit detects the
limit sensor signal input (to be converted to Communications cycle) ×
communications cycle
• When Communications cycle: Unit Cycle = 1:1, 9 scans
Section 4-2
P5AA05 [on Motor]
×
P5AA06 [on Machine]
= 240000 [command unit/min]
= 0.228 [r/min] = 0.22 [r/min]