Speed Control - Mitsubishi Electric MELSEC-L02SCPU User Manual

7.7.5

Speed control

After accelerating to the command speed, the axis continues to operate at the command speed until the Axis stop
instruction (IPSTOP1) is executed. Speed control is implemented in forward and reverse directions. Operation timings
are shown in the figure below.
(1) Speed control operation
(a) Operation timings
V
Start instruction execution
command
Axis 1 BUSY (SM1840)
Axis stop instruction
execution command
Axis 1 positioning complete
(SM1841)
Axis 1 current feed value
(SD1840, SD1841)
(b) Axis 1 positioning completion (SM1841) and Axis 1 current feed value (SD1840,
SD1841)
The Axis 1 positioning completion (SM1841) does not turn on during speed control. Also note that the Axis 1
current feed value (SD1840, SD1841) is fixed to 0 during speed control.
(2) Precautions
(a) Speed 0
When the bias speed at start is set to 0 and the command speed is also set to 0 under the speed control, the
special relays and registers assume the following status. To continue with the operation, set a value other than
0 for the new speed value and then turn off the Axis 1 speed 0 (SM1844) using a speed change request with
the Speed change instruction (IPSPCHG1(P)).
• Axis 1 speed 0 (SM1844): On
• Axis status: Stop
• Axis 1 axis operation status (SD1844): 10 (In speed control)
• Axis 1 busy (SM1840): On
If the bias speed at start is other than 0, changing the command speed to 0 generates an "Out of speed range"
warning (Axis 1 warning code: 1020) and the axis operates at the bias speed at start.
Bias speed at start
ON
OFF
ON
OFF
OFF
OFF
0
CHAPTER 7 POSITIONING FUNCTION
Command speed
t
7
ON
101