User's Manual

HARSFEN0602

3 Communication With the Host

3.1 General

3.2 RS232 Communications

The Harmonica can communicate by RS232 with baud rates up to 115200baud/sec.

The maximum baud rate depends in the sampling time. The baud rate of 115200baud/sec

works only when TS equals or is less than 70. The communication rate of 57600 baud/sec

works with all sampling time options.

Please refer to PP[] command in the Command Reference Manual.

3.2.1 RS232 Basics

The RS232 method can only serve to communicate a host to a single amplifier. The RS232 lines are full

duplex – they can carry bidirectional communications. This means that the host can transmit to the amplifier

whenever it finds it right, without considering the state of the amplifier.

The RS232 communication consists of ASCII printable characters only, with some exceptions:

The characters 0xD (carriage return).

Some non-printable characters that are used as error codes. Please refer to EC command in the

Command Reference.

The basic syntax for RS232 commands may be an assignment,

Or a free evaluation:

Where

Item Description

Command mnemonic Two letters (case insensitive) assigned to a command. Please see the

Command Reference manual for a complete list of command

mnemonics.

Index The index, if the mnemonic refers to a vector parameter or command.

Equal sign The ‘=’ character (Optional, if the command assigns a value to a

parameter)

Value Parameter value (Optional, if the command assigns a value to a

parameter)

The parameter value may be any legitimate arithmetic or functional

expression, as explained later in this section.

Terminator

<CR>

or ‘;’.

Table 3-1 – RS232 Rx Item Description

An assignment evaluates an expression and stores the result in a variable.

A free evaluation evaluates an expression and sends the result to the terminal.

Typical examples are:

MO<CR>

Asks the amplifier to report the value of the variable MO.

MO=1<CR>

<CR> is a carriage return, which is the character 0xd (13 decimal).