script/tutorial/53_DirectEpicsAccess.js

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+/////////////////////////////////////////////////////////////////////////////////////////////////// 
+// EPICS direct channel access.
+// EPICS devices implemented are included in PShell, package ch.psi.pshell.epics.
+// However direct channel access builtin functions are available.
+/////////////////////////////////////////////////////////////////////////////////////////////////// 
+
+
+channel_name = "TESTIOC:TESTCALCOUT:Output"
+
+//reading/writing to a channel
+print (caget(channel_name))
+caput(channel_name, 0.0)
+//Put with no wait
+caput(channel_name, 0.0)
+print (caget(channel_name))
+
+//waiting for a channel value
+cawait(channel_name, 0.0, timeout = 10.0)
+
+//If many IO it is better to keep the same CA connection
+channel = create_channel(channel_name, 'd')
+for (var i=0; i<10; i++){
+    print (channel.get()
+)
+}    
+channel.close()
+
+
+//The create_channel_device method return a device implements Readable and Writable and therefore can be used in scans
+channel = create_channel_device(channel_name, 'd', null, "My Channel")
+lscan(channel, ai2, 0, 10, 0.1)
+channel.close()
+
+
+//Or else we can use a Device
+ChannelDouble= Java.type('ch.psi.pshell.epics.ChannelDouble')
+channel = new ChannelDouble("My Channel", channel_name)
+channel.initialize()
+lscan(channel, ai2, 0, 10, 0.1)
+channel.close()
+
+
+
+//Creating a table reading set of channels for each scan step.
+attrs_dataset = null
+attrs_names = ["TESTIOC:TESTCALCOUT:Input",
+    "TESTIOC:TESTCALCOUT:Output", 
+    "TESTIOC:TESTSINUS:SinCalc",
+    "TESTIOC:TESTWF2:MyWF"]
+attrs_types = ["d", "d", "d", "[d"]
+attrs_lenghts = [0,0,0,10]
+
+
+function AfterReadout(rec){
+    if (attrs_dataset == null){
+        attrs_dataset = get_exec_pars().group + "attributes"
+        create_table(attrs_dataset, attrs_names, attrs_types, attrs_lenghts)    
+    }
+    record = []
+    for (var i=0; i<attrs_names.length; i++){
+    	val = caget(attrs_names[i], attrs_types[i])
+        record.push(val)
+    }
+    //print record
+    append_table(attrs_dataset, record)   
+}    
+
+a = lscan(m1, [ai1, ai2], 0, 0.1, 20, 0.01, undefined, undefined, undefined, undefined, after_read=AfterReadout)