Introduction to I/O Servers

From HSYCO
Revision as of 16:21, 28 February 2014 by Giampiero (talk | contribs)
Jump to navigation Jump to search

An I/O Server is the logical representation of a field system integrated in HSYCO. A field system can be, for instance, a security system, a BUS network or even something more abstract as weather information gathered from the internet.

All I/O Servers provides for datapoints through which they receive commands and/or trigger events. That is, you can use these datapoints in your programming logic or user interface to send commands to the field system or to act upon its changes.

The first step when integrating a new system is to configure the corresponding I/O Server. This is accomplished using the I/O Servers section of the Settings application accessible through the Manager.

From here you can specify the communication parameters and its options. Details of this settings are provided in the I/O Servers application notes for each integrated system.

Using Datapoints

All the available datapoints for an I/O Server are detailed in its application note. A datapoint can be readable (R) and/or writable (W).

Let's introduce these concepts with an example. Assume an I/O Server has the following datapoints table:

ID Value R/W Description
foo 1 R ...
2 R ...
reset W ...
bar a R ...
W ...
b R ...
W ...
unknown R ...

This table specifies that this I/O Server has 2 datapoints: "foo" and "bar". If we read the "foo" datapoint, we can see 2 possible values: "1" or "2", further we can write only the value "reset" to it. On the other hand the "bar" datapoint can be read in three different states ("a", "b" or "unknown") and we can set it to the values "a" and "b".

If a datapoint is both readable and writable, writing a value to it doesn't mean that a subsequent reading will yield the same value, it simply means that we are issuing a command to the I/O Server. For instance, after setting a datapoint representing a light to "on", we will continue reading its value as "off" until the field system notifies HSYCO that the light is actually on


Readable Datapoints

The main use for readable datapoints is to execute actions when they trigger an event. This can be in Events Programming using the event keyword "IO" or in JavaScript or Java Programming using the callback method IOEvent