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--- scripting_for_plc_servers [2020/09/06 20:25]
wikiadmin
+++ scripting_for_plc_servers [2021/09/10 16:09] (current)
wikiadmin
@@ Line 1: / Line 1: @@
-==== TransSECS Devices - Scripting for PLC Servers ====
+===== TransSECS Devices - Scripting for PLC Servers =====
 To write a value to a server in the devices the format is:
@@ Line 30: / Line 30: @@
 </code>
-**Register for Connection Status Notification in TransSECS Host Application**
+==== Set a value to a field in a message and send the message ====
+<code javascript>
+var TransSecsController = Java.type("com.ergotech.transsecs.secs.TransSecsController");
+secsInterface=TransSecsController.findController("PLCTool");  // the name of your project
+// find the message
+var message = secsInterface.getMessageBean("MessageName");  // the name of your message
+message.setSlotNumber(15);  // "SlotNumber" is the name you gave to an element in TransSECS when the message "MessageName" was defined.
+message.sendMessage();
+</code>
+Here's a more concrete example. In an S2F42/S2F50 reject response set the CPName to indicate which parameter is in error:
+<code javascript>
+  //function to send a host command reply with an invalid parameter
+ function sendBadParamReply(paramName) {
+   reply = secsInterface.getMessageBean("HostCommandRejectedBadParam");
+   reply.setCPName(paramName);
+   reply.sendMessage();
+  } //end of function to send HostCommandRejectedBadParam
+</code>
+A function to set the HCACK on an S2F42/S2F50 message.  Note that the HCACK is a little strange. In TransSECS all byte types (SECS format 10) take an array, so here we have to create an array.
+<code javascript>
+ //function to send a simple host command reply
+ function sendSimpleReply(hcack) {
+   reply = secsInterface.getMessageBean("HostCommandReply");
+   reply.setHCACK(Java.to([hcack],"byte[]"));
+   reply.sendMessage();
+  } //end of function to send HostCommandReply
+</code>
+==== Register for Connection Status Notification in TransSECS Host Application ====
 In a GEMHost application the TransSECS controller publishes the status of the connection.
@@ Line 63: / Line 98: @@
 The details of the connection status are [[programmatic_host_connection_status|described here]]
-**Sending a List to PLC Registers**
+==== Writing a List to PLC Registers ====
 If a message is received from the host contains a list of variable length it's easy to split this list and place it in registers on the PLC.
@@ Line 99: / Line 134: @@
 </code>
+==== Reading a Variable Length List from a PLC and updating a VID ====
+The most challenging part of reading the list from the PLC is managing the length of the list.
+Here we trigger the script on the variable that is the list length (ListVIDLengthFromPLC)
+{{:pasted:20200908-192009.png}}
+and use that script to populate a VID "ListVID"
+{{:pasted:20200908-192109.png}}
+The register VIDListArray is used to read the elements of the list individually.
+After reading the list from the PLC and setting the VID, the script resets the length variable in the PLC ready for the next update of the variable.
+<code javascript>
+var TransSecsController = Java.type("com.ergotech.transsecs.secs.TransSecsController");
+var SecsFormat20 = Java.type("com.ergotech.secs.SecsFormat20");
+var SecsFormat00 = Java.type("com.ergotech.secs.SecsFormat00");
+var LongValueObject = Java.type("com.ergotech.vib.valueobjects.LongValueObject");
+listLength = incomingValue.getIntValue();
+//print ("List Length "+ listLength);
+try {
+    if ( listLength > 0 ) { // will reset this to zero after update
+        print ("List Length "+ listLength);
+        secsInterface=TransSecsController.findController("PLCTool");
+        gh = secsInterface.getGemHandler();
+        listValue = new SecsFormat00();
+        for (id =0 ; id < listLength ; id++ ) {
+            /Devices/NJPLC_Servers/VIDListArray->setVariableName("StringArray[" + id + "]");
+            /Devices/NJPLC_Servers/VIDListArray->triggerRead();
+            incomingString = /Devices/NJPLC_Servers/VIDListArray->getStringValue();
+            listValue.add(new SecsFormat20(incomingString));
+        }
+        print ("List "+ listValue);
+        gh.setValue("ListVID",listValue);
+        /Devices/NJPLC_Servers/ListVIDLengthFromPLC->setValueObject(new LongValueObject(0));  // reset the length
+    }
+} catch ( e ) {
+    print ("Error " + e );
+}
+;  // update the server with a zero...
+</code>
+If the PLC Device supports an Array type, you can use this value directly in the Device Name/Tag Name dropdown.  The values from the array will be automatically converted from the type in the array to the SecsFormat type.
+For a ModbusArray, the conversion is as follows:
+{{:pasted:20210129-100944.png}}
+Unsigned Word - SecsFormat52
+Signed Word - SecsFormat54
+Unsigned Double Word - SecsFormat50
+Signed Double Word - SecsFormat50
+Float - SecsFormat44
+Coil - SecsFormat11
+Discrete - SecsFormat11
+For an S7 Array the conversions X,B,W,I,D all convert to SecsFormat5. R (real) convert to SecsFormat44 and S (String) to SecsFormat20.
+For improved control over the conversion, the SecsFormat00 can be created in a script.
+In this example we create a SecsFormat00 containing signed integers  - SecsFormat34
+<code javascript>
+var TransSecsController = Java.type("com.ergotech.transsecs.secs.TransSecsController");
+var SecsFormat34 = Java.type("com.ergotech.secs.SecsFormat34");
+var SecsFormatValueObject = Java.type("com.ergotech.secs.gem.SecsFormatValueObject");
+var SecsFormat00 = Java.type("com.ergotech.secs.SecsFormat00");
+listValue = new SecsFormat00();
+try {
+        secsInterface=TransSecsController.findController("PLCTool");
+        gh = secsInterface.getGemHandler();
+        for (id =0 ; id < incomingValue.size() ; id++ ) {
+            listValue.add(new SecsFormat34(incomingValue.get(0).getIntValue()));
+        }
+        print ("List "+ listValue);
+        gh.setValue("ListVID",listValue);
+    }
+} catch ( e ) {
+    print ("Error " + e );
+}
+new SecsFormatValueObject(listValue);
+</code>
+==== Reading a File and Storing as Binary Data in the PLC ====
+This example uses the Melsec Binary (MelsecBinary) server.  It reads a file from the disk, compresses the file and sends it to the server.
+<code>
+var Deflater = Java.type("java.util.zip.Deflater");
+var Inflater = Java.type("java.util.zip.Inflater");
+var Files = Java.type("java.nio.file.Files");
+var BinaryValueObject = Java.type("com.ergotech.vib.valueobjects.BinaryValueObject");
+var LongValueObject = Java.type("com.ergotech.vib.valueobjects.LongValueObject");
+var arrayOfBytes = Java.type("byte[]");
+recipe = Files.readAllBytes(java.nio.file.Paths.get("DemoPPBody.rcp"));
+// Compress the bytes
+output = new arrayOfBytes(2000);
+compresser = new Deflater();
+compresser.setInput(recipe);
+compresser.finish();
+compressedDataLength = compresser.deflate(output);
+compresser.end();
+outArray = new arrayOfBytes(compressedDataLength);
+java.lang.System.arraycopy(output, 0, outArray, 0, compressedDataLength);
+// save the length of the compress recipe to the PLC using a server called "CompressedRecipeLength"
+CompressedRecipeLength->setValueObject(new LongValueObject(compressedDataLength));
+new BinaryValueObject(outArray);  // will be writen to the server
+</code>
+The inverse of the above code reads the bytes from the PLC and stores them to a file.
+<code>
+var Deflater = Java.type("java.util.zip.Deflater");
+var Inflater = Java.type("java.util.zip.Inflater");
+var Files = Java.type("java.nio.file.Files");
+var BinaryValueObject = Java.type("com.ergotech.vib.valueobjects.BinaryValueObject");
+var StringValueObject = Java.type("com.ergotech.vib.valueobjects.StringValueObject");
+var arrayOfBytes = Java.type("byte[]");
+// read the length of the compress recipe from the PLC using a server called "CompressedRecipeLength"
+CompressedRecipeLength->triggerRead();  // force an update
+compressedDataLength = CompressedRecipeLength->getIntValue(); // and read the latest value.
+java.lang.System.out.println  (" Compressed DataLength " + compressedDataLength);
+// Compress the bytes
+output = new arrayOfBytes(2000);
+inflater = new Inflater();
+buf = incomingValue.getBinaryValue();
+inflater.setInput(buf,0,compressedDataLength);  // assumes that the compressed data length is always less than the length read from the server (setLength))
+resultLength = inflater.inflate(output);
+inflater.end();
+// trim the array to the size of of the output
+outArray = new arrayOfBytes(resultLength);
+java.lang.System.arraycopy(output, 0, outArray, 0, resultLength);
+Files.write(java.nio.file.Paths.get("DemoPPBody.rcp.out"), outArray);
+</code>