K-Patents PR-23 - Manual (Page 181)

12 Ethernet connection specification 173
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 identifiers (see Section 12.5.2 for additional information) are
case-insensitive. However, K-Patents recommends that they are written as in this
specification.
The server (DTR) may send the response keys in any order. It will send the manda-
tory keys (marked with an asterisk in Section 12.5.2) of the specific request, but it
may omit any other keys. The server may also send keys that are not specified 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 specification
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 as-
terisk (*).
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.