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Webpanel API
Communication is based on HTTP protocol. Clients send HTTP POST request and get the response depending on the request. Each request must specify the credentials in case the credentials are specified for the project.
Login
Request
Data:
{
ver : 1,version
optional - only for non-authenticated access
credentials
c: {u: “karel”, p: “x”}
}
==== Response ====
{
ver : 1,version
code: “ok”, return code
msg: “”, error message
c : {u: “karel”, p:”x”} must be used for further communication
}
===== Data request =====
==== Request ====
Data:
{
ver : 1,version
optional - only for non-authenticated access
credentials
c: {u: “karel”, p: “x”},
variable IDs
v: [ “svc:defaultConnection/myVarId1”,
“svc:otherConnection/xxxYYYYDDD”]
}
* variable ID is unique string - in future, may be different for different platforms/protocol versions (uPLC - int?, SharkRT - string)
=== Variable specification for RT2 ===
* svc - protocol
* Connection - generally, clients can request data from more sources (more or less corresponds to a connection definition of PLC). For local data (data belonging to the PLC that executes the request) it may be defaultconnection.
* Variable id: it has a form of commUID[offset, lenght]. CommUID can be retrieved from a .vlist file of the IDE 2 project and specifies a variable. Variables can be of a complex and large types. In this case a user can retrieve only a small part of the variable by using the offset and length.
* Example: svc:defaultConnection/877* 0,2]
* Represents a variable with the commUID 8776. 2 bytes from the offset 0 are returned.
the POST body can be:
- JSON string (AngularJS default behaviour):
{“ver”:1,“c”:{“u”:“karel”,“p”:“x”},“v”:[“svc:defaultConnection/myVarId1”,“svc:otherConnection/xxxYYYYDDD”]}
- converted into POST parameters (jQuery default behaviour):
ver=1&c%5Bu%5D=karel&c%5Bp%5D=x&v%5B%5D=svc%3A%2F%2FdefaultConnection%2FmyVarId1&v%5B%5D=svc%3A%2F%2FotherConnection%2FxxxYYYYDDD
The best solution would be to support both versions. Easier is now the JSON string.
==== Response ====
{
ver : 1,version
code: “ok”, return code
msg: “”, error message
v: [{
i: “svc:defaultConnection/myVarId1”, variable Id
v: ”ACA1”, value - binary encoded
q: “G”,quality
t: 654654321654 timestamp UTC, milliseconds since 1970
}
]
}
=== Encoding of values - version 1 ===
Ea * Unordered List Itemch value is transmitted as a big endian binary representation of the specified variable (and its offset and length).
===== Command Request =====
==== Request ====
{
ver : 1,version
optional - only for non-authenticated access
credentials
c: {u: “karel”, p: “x”},
v: [{
i: “svc:defaultConnection/myVarId1”, variable Id
digital setter
time: ”20.0”, digital setter has some time property…
state: “2”, state that should be applied
defaultValue: “6”, some default value
analogPlusMinusInit, TPG, …
set: 5,
set: “<?cdata….?>” TPG
login - pin
login: “1234”
}
]
}
===== Configuration Response =====
* Warning : only one variable is expected in the request for the tiniest (uPLC) platforms - other variables are ignored
===== Historical Data Request =====
==== Request ====
{
ver : 1,version
optional - only for non-authenticated access
credentials
c: {u: “karel”, p: “x”},
v: [ {i:“svc:defaultConnection/myVarId1”,
from: XXXX,
to: YYYY
},
{i:“svc:defaultConnection/myVarId1”,
from: XXXX,
to: YYYY
}
]
}{
ver : 1,version
platform: “uPLC”,
maxVariablesInRequest: 5,
maxRequestSize: 1500, http body size in bytes
preferedLanguage: “en-US”
}
====== Native/built-in data types ======
Note: big endian encoding (v1)
* integer (represents int8-int64)
* unsigned integer (represents uint8-uint64)
* double (double64)
* float (float32)
* bool (boolean - 0 ~ false, 1 ~ true)
* dt (date time - the number of 100-nanosecond intervals that have elapsed since 12:00:00 midnight, January 1, 0001)
* time (time - the number of 100-nanosecond intervals)
* Enums are encoded into 32-bit int