Message and Terminator
This section provides terminology and details concerning communication between the power supply controller and devices.
The program messages and response messages supported by a device are called "device messages."
The availability of a message depends on the type of control board mounted and DC power-supply unit connected.
The messages transmitted from the controller to a device are called “program messages.” The messages transmitted from a device to the controller are called “response messages.”
Each message is composed of a program header and data.
There are two types of program messages: command messages and query messages.
A command message is used to execute a specified function of a device and to alter settings. A query message is used to inquire about the settings and status of a device.
Writing program messages
Provide a space (ASCII: 20h) between the program header and the data.
When there is more than one piece of data, connect them using “, ” (ASCII: 2Ch).
To connect one program message to another, use “;” (ASCII: 3Bh).
To describe data using hexadecimal numbers, add “#H.”
Example: To describe the decimal number “10” using a hexadecimal number, write “#H0A.”
When “@” is added to the end of a program message, the hold-off status is retained until execution of the message is completed. However, in the event of a program message terminator with only EOI, use “@@”.
Acknowledgement messages (RS232C)
The acknowledgement message is peculiar to the RS232C interface. This message is sent from the power-supply controller to a terminal. It indicates that a program message has been processed.
An acknowledgement message is a character string of ASCII code which is composed only of a header. There are two types such messages:
OK: Normally terminated
ERROR: Abnormality occurring, such as a syntax error
Through the use of a SILENT command message, it can be specified whether to return an acknowledgement message.
The terminator used to indicate that a program message has been terminated is called a “program message terminator.” The terminator used to indicate that a response message has been terminated is called a “response message terminator.”
Program message terminators
One of the following may be used. No preliminary settings are required.
Response message terminators
CR+LF+EOI is set by default. Using either a TRM or DELIMITER command message, it can be changed to one of the following: