The response data sent by the instrument is in ASCII format. With the exception of the packet number, the data is human-readable. The data structure is very simple:
- Packet number (32-bit integer)
- Zero or more lines of ASCII (text) keys and values associated with these keys (for example temperature key and process temperature in Celsius)
The packet number is echoed back without change. The client (software on computer) can use the packet number to check the response against the packet number of the request.
The message text consists of lines of text, each line a single key (of one word) and its value or values. The values are separated from the key by an equal sign ( = ) and multiple values are separated by a comma. White space (space or tabulator) is allowed anywhere except within a single value or key name.
If the response consists of a character string, it is enclosed in double quotes ("). For example, all these are valid message text lines:
oktemp = 23.45headhum = 13.32LEDcnt = 8341ChemCurve = 1.234, 3.21, 0.00, 4.37, 1.11, 0.00002, 2.1345StatusMessage = "Normal Operation"| All the key identifiers are case-insensitive. For more information, see Request-response pair specification. However, the recommendation is that they are written as in this specification. |
The server (refractometer) may send the response keys in any order. It sends the mandatory keys of the specific request, but may omit any other keys. The mandatory keys are marked with an asterisk in Request-response pair specification.
The server may also send keys that are not specified in this document, but the client (computer) may ignore them.