Rockwell Automation 2098-DSD-xxx Ultra3000 Host Commands for Serial Interface - Manual (Page 169)

Publication 2098-RM003A-EN-P October 2001
Using Host Commands C-5
Exercise #2 – Controlling
Speed in Host Mode This exercise issues a host command to set the speed of the motor. It
builds on the Ultra family command previously issued to place the
drive in velocity set point control mode. The command string
parameters to set the motor speed to 500 rpm are:
Note: The numbers are hexadecimal.
1. Convert 500 rpm to an 8 character, hexadecimal value. Assume a
standard encoder with 2000 lines per revolution (8000 counts/rev)
to calculate the hexadecimal data value:
2. Calculate the checksum and convert to hexadecimal by subtracting
760 from 256 (256 - 760 = -504), and converting -504 to hex
(0xFFFFFE08).
3. Prefix the string with a colon and append the two least significant
digits of the hex value (08) to the end of the command string.
4. Type the command string into Hyperterminal followed by the
Enter key. The motor will rotate at 500 rpm when the drive is
enabled.
5. Stop the motor using the same command by setting the speed to
zero (0) rpm.
Command String :0006D100012EBCcc Parameters
cc Checksum
00012EBC Data
1 Function
06D Parameter
00 Drive Address
Encoder Conversion 1 rpm = 8000 counts/minute or 155 counts/second
Hex Conversion 500 rpm = 77,500 counts/second or 0x12EBC hex
Hex Character 0 0 0 6 D 1 0 0 0 1 2 E B C c c
ASCII Value 48 48 48 54 68 49 48 48 48 49 50 69 66 67
ASCII Sum — 96 144 198 218 267 315 363 411 508 558 627 693 760
Hex Conversion 256 - 760 = 0xFFFFFE08 Hex
Command String :0006D100012EBC08