IAI America PSEL - Manual (Page 194)

184
Part 2 Programs
 CHVL (Change speed)
Command, declaration
Extension condition
(LD, A, O, AB, OB)
Input condition
(I/O, flag)
Command,
declaration
Operand 1 Operand 2
Output
(Output, flag)
Optional Optional CHVL Axis pattern Speed CP
[Function] Change the speed of the axes operating in other task.
When a CHVL command is executed, the speed of the axes specified in operand 1 will change to
the value specified in operand 2.
(Note 1) This command is not valid on an axis operated by a CIR, ARC, PSPL, PUSH, or ARCH command.
(Note 2) Executing a CHVL command for an axis operating in sigmoid motion (SCRV command) will
generate an “Error No. CC1, Speed-change condition error.”
(Note 3) This is a temporary speed-change command issued from other task to the active packet (point). It
is not affected by the data declared by VEL.
Program 1 Program 2
VEL 300


MOVP 1
CHVL 11 100 MOVP 2
MOVP 3


The axis pattern can be specified indirectly using a variable.
When program 1 is rephrased based on indirect specification using a variable:
11 (binary)
 3 (decimal)
LET 1 3 Assign 3 to variable 1.
CHVL *1 100
(Note 4) Since this command is valid only for the packet that is active at the time of execution of the
command for an axis subject to continuous motion in a PATH command, etc., caution must be
exercised against the timing shift. The packet handling will be put on hold during speed-change
processing, so caution must also be exercised against the locus shift.
Program 1 Program 2

VEL 300
 
 
CHVL 11 100 PATH 1 5



If CHVL is executed in program 1 while PATH is executed in program 2, or specifically during the
PATH movement from point No. 2 to point No. 3, the speed specified by CHVL (100 mm/sec in the
above example) will become valid only during the PATH movement to point No. 3. Other travel
speeds will remain at the speed specified by VEL (300 mm/sec in the above example).
(Note 5) Override of the CHVL call task will be applied, so caution must be exercised.
(Note 6) The maximum speed of the specified axis completing home return will be clamped by the minimum
value set in “Axis-specific parameter No. 28, Maximum operating speed of each axis” or
“Axis-specific parameter No. 27, Maximum speed limited by maximum motor speed” with respect
to the specified axis and related interpolation axes currently operating. To prevent the maximum
speed from being limited due to the effect of other axis whose maximum speed is lower than the
speed specified in the CHVL command, issue a CHVL command in multiple steps corresponding
to the respective axes having different maximum speeds. In particular, specification of a CHVL
command in a separate step is recommended for a rotating axis.
[Example] CHVL 11 500  CHVL 1 500
CHVL 10 500
No. 1 No. 3 No. 5
No. 2 No. 4
VEL 100
If CHVL is executed in program 1 while MOVP 2
is executed in program 2, the travel speed of
MOVP 2 will become 100 mm/sec.
The speeds of other move commands will
remain 300 mm/sec.