Rockwell Automation 2098-DSD-xxx Ultra3000 Host Commands for Serial Interface - Manual (Page 168)

Publication 2098-RM003A-EN-P October 2001
C-4 Using Host Commands
Exercise #1 – Enabling
Setpoint Velocity Control This exercise transmits the command that places the drive in the
setpoint velocity Host Control Mode, which allows the drive to accept
velocity commands using host commands. The command string
parameters to enable the Setpoint Velocity Host Control Mode are:
Note: The numbers are hexadecimal.
1. Calculate the checksum.
Note: The colon that signifies the beginning of a command is
ignored when calculating the checksum.
A. Sum the ASCII values for each character in the command
string. Refer to ASCII Conversions on page C-8 for the ASCII
values.
B. Subtract 393 from 256.
C. Convert –137 to hexadecimal (–137 = 0xFFFFFF77 Hex).
Note: Use the Windows calculator feature to convert –137 to a hex
value. The calculator is in the Accessories section. Be sure to
switch it to scientific functions.
2. Assemble the complete command by appending the two least
significant digits of the checksum hex value, 77, to the end of the
command string and prefixing the string with a colon.
3. Type the command string into Hyperterminal followed by the
Enter key. The Ultra3000 drive is now ready to accept velocity
commands.
Command String :00061101cc Parameters
cc Checksum
01 Data
1 Function
061 Parameter
00 Drive Address
Hex Character 0 0 0 6 1 1 0 1 c c
ASCII Value 48 48 48 54 49 49 48 49
ASCII Sum — 96 144 198 247 296 344 393
256 - 393 = -137
Command String :0006110177