Specifications

LA Series Linear Servo Amplifier Technical Reference Manual

13 Appendix A. Serial Communication Messages

This section describes the details of the serial communication messages. The only white space

character used in this protocol is the Space (ASCII 0x20). All lines are terminated with a Carriage

Return and Line Feed (cr/lf) followed by a “>” prompt (ASCII 0x3E). The prompt is sent following

any message by the amplifier. The prompt line has no termination in order to allow a dumb

terminal cursor to remain on the prompt line. This provides a clear indication for the user when

the amplifier is ready for a new command when using a dump terminal interface.

Some common characters used in this section are:

cr = Carriage Return, ASCII 0x0D

lf = Line Feed, ASCII 0x0A

> = Greater Sign (used as the prompt), ASCII 0x3E

When the amplifier is first powered up, the user must wait until the sign on message and the

prompt are sent before normal communication can begin. The sending of the first prompt from

the amplifier means it is ready for operation. If a fault alarm is present on power up, the fault

message will be shown followed by a prompt.

All command sent to the unit must be in upper-case characters. Messages that the amplifier

sends for a particular command or condition are a fixed length. Messages are padded with the

space (ASCII 0x20) to achieve the desired length. As an example, all alarm messages are 14

characters in length.

All messages from the amplifier are shown in quotes to allow the programmer to determine the

character count for each message. The quotes are not part of the message. Any blank lines sent

by the amplifier are shown by the cr/lf sequence in the text shown below.