12 Ethernet connecon specicaon
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Response format
The response data sent by the DTR 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 com-
puter) 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:
ok
temp=23.45
headhum = 13.32
LEDcnt = 8341
ChemCurve = 1.234, 3.21, 0.00, 4.37, 1.11, 0.00002, 2.1345
StatusMessage = "Normal Operation"
Note: All the key identiiers (see Section 12.5.2 for additional information) are case-
insensitive. However, K-Patents recommends that they are written as in this specii-
cation.
The server (DTR) may send the response keys in any order. It will send the mandatory
keys (marked with an asterisk in Section 12.5.2) of the speciic request, but it may omit
any other keys. The server may also send keys that are not speciied in this document,
but the client (computer) may ignore them.
Request and response errors
When the server (DTR) detects an error, it responds with an error message (for more
information see Section 12.5.3). An error message can be caused for example by an
unknown request or inability to collect data for the mandatory keys of a response.
12.5.2 Request-response pair specicaon
The list below describes the query messages, i.e. request-response pairs, used for data
collection via Ethernet. Mandatory response keys are preceded by an asterisk (*).
Note: Even when multiple request data options are available, only one can be used
at a time. For example each sensor status request must be directed to either sensor A
or sensor B, not both.
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