Command Format And Controller Response; Binary Command Format - Galil Motion Control DMC-1600 Series User Manual

Command Format and Controller Response

Instructions may be sent in Binary or ASCII format. Binary communication allows for faster data processing since
the controller does not have to first decode the ASCII characters.
ASCII Command mode
In the ASCII mode, instructions are represented by two characters followed by the appropriate parameters. Each
instruction must be terminated by a carriage return or semicolon.
The controller decodes each ASCII character (one byte) one at a time. It takes approximately 350 sec for the
controller to decode each command and execute it.
After the instruction is decoded, the controller returns a colon (:) if the instruction was valid or a question mark (?) if
the instruction was not valid.
For instructions that return data, such as Tell Position (TP), the controller will return the data followed by a carriage
return, line feed, and colon (:).
An echo function is also provided to enable associating the response with the command sent. The echo is enabled
by sending the command EO 1 to the controller.
Binary Command Mode
Some commands have an equivalent binary value for the controllers. These values are listed in the Command
Reference next to the command in parentheses in hexadecimal format . Binary communication mode can be
executed much faster than ASCII commands since the controller does not have to first decode the ASCII characters.
Binary format can only be used when commands are sent from the PC and cannot be embedded in an application
program.

Binary Command Format

All binary commands have a 4 byte header followed by data fields. The 4 bytes are specified in
hexadecimal format.
Binary Header Format:
Byte 1 specifies the hexadecimal command number between 80 to FF.
Byte 2 specifies the # of bytes in each field as 0, 1, 2, 4 or 6 as follows:
Byte 3 specifies whether the command applies to coordinated motion on the "S" or "T" axis as follows:
DMC-1600
00 No datafields (i.e. SH or BG)
01 One byte per field
02 One word (2 bytes per field)
04 One long word (4 bytes) per field
06 Galil real format (4 bytes integer and 2 bytes fraction)
Bit 1 = T axis coordinated motion movement
Bit 0 = S axis coordinated motion movement
Chapter 4 - Software Tools and Communications • 53