Elmo HARSFEN0602, HARmonica Echo, Background Transmission, Errors and exceptions in RS232

HARSFEN0602ElmoHARmonicaSoftwareManual PRELIMINARYDRAFT

Sets the value of 1 to the MO variable. CA[2]=1;

Sets the value of the CA[2] variable. CA[N] denotes a vector of parameters that can be accessed by their index.

The free evaluation (5+sin(PX))*sqrt(abs(VX))

Returns numerical value to the terminal.

More detail about text interpreting is given in the chapter "The Interpreter Language".

The amplifier responds to the host communicated commands. It never initiates an unasked-for message to the host.

The syntax of the amplifier answers is {<Value>}{<Error code>}<Terminator> Where

Item	Description
Value	Parameter value (Optional, if the command asks to report parameter)
Error code	A binary number that may be interpreted according to the error code tables –
	please refer the EC Command in the Command Reference Manual.
Terminator	‘;’ if the host command has been successfully executed, else ‘;?’
	Table 3-2 – RS232 Tx Item Description

3.2.2The Echo

When using RS232 each character that is received by the amplifier is echoed back to the host. The echo is immediate, per each received character.

3.2.3Background Transmission

When the host enters the BH=n command to the amplifier, the amplifier uploads the recorder data to the host. The uploading process may take few seconds. At the time the amplifier uploads records to its host, it is still listening to the host for new commands.

Consider the command sequence BH=1;MO=0<CR>

The amplifier will start to transmit the recorder data immediately. Few milliseconds later, while the recorder data is still transmitting, the amplifier will execute the MO=0 command. The amplifier will store the response message to the MO=0 command, in order to transmit it later, immediately after the records upload terminates.

Note:

If the host does not know the communication parameters, it may transmit a series of terminators and try several baud rates, until it can receive a matching sequence of echoes.

3.2.4 Errors and exceptions in RS232

If an error is intercepted (Overrun, noise, parity, framing), then the entire message including this error is discarded, and answered by the “communication error” code response.

Although the communication is defined as 8 bits per character, only the byte values 0-127 are used. The characters 127-255 are treated as UART errors.

Empty strings with terminators are echoed back, but otherwise ignored.

3.3CANopen Communication

A detailed description of CANopen communications is out of the scope of this manual. Please refer the CANopen Manual.

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