Party Line and Daisy Chain Line Commands, Some Rules

ADVANCED MICRO SYSTEMS, INC.SERIAL INTERFACE

Edit Program

Example: It is desired to change instruction number 21 from 500 steps to 5,000 steps:

Enter	Remark
P21<CR>	Edit instruction 21.
R5000	Move 5,000 steps in the “+” direction, relative to Origin.
“ESCape”	Terminates Edit mode.

Note: Caution should be exercised when making Program Edits in dumb terminal mode due to variations in command byte length that may effect subsequent command address locations and possible corruption of non-volatile memory storage. It is recommended that application programs be developed using the menu driven program (Party Line selection) in the EASI diskette, which includes a sophisticated Editor and Compiler.

Party Line and Daisy Chain Line Commands

Note: If a SIN-10 is used in the “intelligent” mode, then the following rules will not apply because the SIN-10 will perform the necessary handshake.

The SMC series controllers incorporate a buffered UART input, capable of receiving and holding ONE character at a time. The controller must read this character before another one is received; otherwise the UART will be over-run, resulting in missed character errors.

The handshake method used is a simple “echo” of the received character. The host computer MUST ALWAYS wait for the echo.

Fixes such as insertion of delays between characters may seem to work but will ultimately fail. Beware that many PLC manufacturers do not provide the serial software flexibility required for your application to make the proper communication.

(The SIN-10 adapter provides handshaking functions and other features to make life simpler and reduce software development time).

Some Rules

1.The first character of a command MUST be the “name” character assigned to the axis.

2.The command line terminator MUST be a Line Feed character.

3.The name must be preceded by an LF (presumably the terminator for the previous command), i.e., <LF>“n” xxxxxxx <LF>.

Note: An LF can be generated using a Ctrl–Enter key combination on a PC.

The first Line Feed “resets” the command buffer for all axes. The controller then tests the character immediately following a Line Feed. If this character matches the assigned “name,” the axis will interpret the following characters (up to 12) as an input command. If the axis does NOT detect a proper name and command, then the data is simply echoed back to the terminal. The designated controller re -issues the Line Feed after processing the command.

If the command is of the type that results in a data output (such as “Z”), then the data (result) will be inserted before the Line Feed. The Line Feed does NOT indicate that a move or other time consuming command is finished but only initiated. The terminal can interrogate the motion status using the appropriate command to determine if a function is complete. Editing features are NOT supported in daisy chain or party line operation.

Note: the commands “Control C” and “ESCape” do NOT require the use of, and will NOT be qualified by, a “name” prefix. All devices will respond.

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