Experimental Physics and
Industrial Control System

Ricardo Herrero <[email protected]> · Tue, 24 Feb 2015 11:46:18 +0100

Hello all,

 I´m a newbie in this environment and I´m trying to understand EPICSv4,

I have tried examples HelloWorld and rdbService from example JAVA in the

last release from EPICSv4-JAVA. Now I´m trying to make a classical

example of a PVServer generating data and clients trying to get it

automatically, so I have a pair of questions that maybe you can help me

to solve.

First: I think that I should try using Monitor to publish/suscribe for

automatic onChange working between a PVServer and a Client, AM I right?

Second: The General architecture for monitor seems a bit complex to me

and I need some help to Undestand it. Here are my thoughts and I want to

Know if I´m right or where I´m mistaken:

First you start the client with ClientFactory.start(). In the client

side you need to get to a ChannelProvider (in this case "pva"). Then you

have to create a Channel from the Provider (but you need a

ChannelRequester and I don´t know if I just have to create the object or

find it in the net).

Continuining with the creation of a PVStructure you can then create also

the Monitor (But I don´t know if when I create the channel, this channel

has to be a ChannelRPC or not). Also, Is the requester of the monitor

the same as the requester of the Channel creation?. Finally I don´t see

the structure of the MonitorElement, and when I create the Monitor, do I

have to make a while loop where I write the commando FOR for the monitor

and get there the MonitorElement?

In the server side I´m even more lost, as I have seen the createMonitor

in ChannelRPC, but I can´t see any of the parameters configuration

(such as the term onChange) that it´s mentioned in the documentation

about Monitor.

If anyone has tested this, I would gladly accept any help.

Thanks in advance, Ricardo

--
Doctorando i2a2
Jefe de Servicio de Instalaciones - CEDEX

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System