Rockwell Automation 2098-DSD-xxx Ultra3000 Host Commands for Serial Interface - Manual (Page 165)

1 Publication 2098-RM003A-EN-P October 2001
Appendix
C
Using Host Commands
Objectives This exercise introduces you to the Ultra family drive host mode serial
communications protocol. Each host mode command requires three
steps:
1. Select the appropriate command code.
2. Format the command correctly.
3. Calculate the checksum.
After completion you will be able to write host mode commands.
Host Mode
Communications Overview A Ultra family drive can be set up and operated from a serial
communications terminal, such as a computer, using the host mode
commands. This mode of operation is particularly useful when the
user wishes to write their own custom program to augment or replace
Ultraware software.
Commands that are sent to the Ultra family drive must follow a
specific format. Each command line starts with a colon, followed by a
two digit drive address, a three digit parameter, a single digit function
command, data of a variable length, a two digit checksum, and is
finalized with a carriage return (<cr>). The command format is shown
below and is more fully explained in Communications Protocol on
page 1-1.:
:0006110177<cr> is an example of a complete command string. This
command communicates to the drive with address 00, issues
command code 061 (host control mode), function code 1 (write
working value) with data 01 (setpoint velocity control mode), and
validates communication of the command with a checksum of 77.
Start Address Parameter Function Data Checksum End
: a a p p p f d ... d c c <cr>