Rockwell Automation 1395 ControlNet Communication Board - Manual (Page 45)

3–31 Configuration & PLC Interfacing
Publication 1395–5.37– March, 1999
Autotune Measure System Inertia This function puts the Drive in the Autotune Mode for measuring
system inertia. When in this mode the Drive determines the total
system inertia including the motor and connected load by accelerating
and decelerating the motor under conditions controlled by the Autotune
firmware.
ATTENTION: When in the Autotune Mode the Drive controls
motor operation using a speed profile determined internally.
Carefully read the Drive Manual section on auto tuning
sequencing prior to using this command. Failure to do so could
result in equipment damage and possible injury to personnel. If
autotuning is performed under PLC control, a hardwired stop
circuit or manual disconnect circuit must be provided to
disconnect power to the motor.
PLC Block Transfer Instruction Data –
Write Read
Size In Elements: 4 4
Processor Type: PLC-5 PLC-5
Destination Address: N40:0-3 N40:0-3
Message Structure –
0
PLC Message Write PLC Message Read
NOTE: Word 4 of the PLC Message Read instruction is broken down
into two bytes. The High byte contains the status bits
The Low byte contains the Drive message length in bytes.
Header
Word 1
0
Function Code
781
Message Length
8 bytes
Header
Word 2
Header
Word 3
Header
Word 4
0
Header
Word 1
0
Function Code
781
See Note
Header
Word 2
Header
Word 3
Header
Word 4
Message Operation – This function puts the Drive in the Autotune
Mode for measuring system inertia. Once in this mode, the Drive
waits for a “START” input to the Drive before beginning the measure
procedure. The procedure gathers information about motor inertia and
connected load inertia by accelerating and decelerating the motor under
conditions controlled by the Autotune firmware.
This function requires the message header only. The status byte will
indicate the success or ineffectiveness of the request.