I am trying to better understand the web services and in particular subscriptions. Using C# I can register as a subscription but there are two main questions with the event data I received
a) When subscribing to a value change the data received does not contain the value of the variable. Just an event that it changed eg.
This is the type of subscription but actually done in C#
curl --digest -u "Default User":robotics -X POST -d "resources=1&1=/rw/rapid/symbol/data/RAPID/T_ROB1/Module1/count;value&1-p=1" "http://127.0.0.1/subscription"
The reply is
"<?xml version=\"1.0\" encoding=\"utf-8\"?>
<html xmlns=\"http://www.w3.org/1999/xhtml\">
<head>
<title>Event</title><base href=\"http://127.0.0.1:80/\"/>
</head>
<body>
<div class=\"state\"><a href=\"subscription/52\" rel=\"group\"></a>
<ul> <li class=\"rap-value-ev\" title=\"value\">
<a href=\"/rw/rapid/symbol/data/RAPID/T_ROB1/Module1/count;value\" rel=\"self\"/></li>
</ul> </div>
</body>
</html>"
b) How can I subscribe to an I/O change in value - I only seem to be able to change in state
This fails:
curl --digest -u "Default User":robotics -d "resources=1&1=/rw/iosystem/signals/testDI;value&1-p=0" -X POST "http://localhost/subscription"
This works
curl --digest -u "Default User":robotics -d "resources=1&1=/rw/iosystem/signals/testDI;state&1-p=0" -X POST "http://localhost/subscription"
but I want the value change.