Посібник по промисловим мережам
ToDo
Бере список блоків instantWriteBlockList та робить з нього writePacketArray.
itemList = instantWriteBlockListglobalWriteBlockListglobalWriteBlockList[0] = itemList[0]NodeS7.prototype.prepareWritePacket = function() {
var self = this, i;
var itemList = self.instantWriteBlockList;
// Список запитів складається зі списку блоків,
// розділеного на фрагменти, доступні для читання PDU.
var requestList = [];
var requestNumber = 0;
// Сортує елементи за допомогою функції сортування за типом і offset.
itemList.sort(itemListSorter);
// Just exit if there are no items.
if (itemList.length === 0) {
return undefined;
}
// Reinitialize the WriteBlockList
self.globalWriteBlockList = [];
// На цей раз ми не робимо оптимізацію.
// Причина в цьому те що може спричинити
// Наприклад якщо ми записуєм M0.1 і M0.2 то оптимізація б спричниа запис MB0,
// який би також записував 0.0, 0.3, 0.4...
// Так само зі змінними MW0 і MW2, записався б весь блок
// Але якщо ви дуже, дуже хочете програму для того щоб це зробити,
// запишіть самі масив
self.globalWriteBlockList[0] = itemList[0];
self.globalWriteBlockList[0].itemReference = [];
self.globalWriteBlockList[0].itemReference.push(itemList[0]);
var thisBlock = 0;
itemList[0].block = thisBlock;
var maxByteRequest = 4 * Math.floor((self.maxPDU - 18 - 12) / 4); // Absolutely must not break a real array into two requests. Maybe we can extend by two bytes when not DINT/REAL/INT. But modified now for LREAL.
maxByteRequest = 8 * Math.floor((self.maxPDU - 18 - 12) / 8);
// outputLog("Max Write Length is " + maxByteRequest);
// Just push the items into blocks and figure out the write buffers
for (i = 0; i < itemList.length; i++) {
self.globalWriteBlockList[i] = itemList[i]; // Remember - by reference.
self.globalWriteBlockList[i].isOptimized = false;
self.globalWriteBlockList[i].itemReference = [];
self.globalWriteBlockList[i].itemReference.push(itemList[i]);
bufferizeS7Item(itemList[i]);
}
var thisRequest = 0;
// Split the blocks into requests, if they're too large.
for (i = 0; i < self.globalWriteBlockList.length; i++) {
var startByte = self.globalWriteBlockList[i].offset;
var remainingLength = self.globalWriteBlockList[i].byteLength;
var lengthOffset = 0;
// Always create a request for a self.globalReadBlockList.
requestList[thisRequest] = self.globalWriteBlockList[i].clone();
// How many parts?
self.globalWriteBlockList[i].parts = Math.ceil(self.globalWriteBlockList[i].byteLength / maxByteRequest);
// outputLog("self.globalWriteBlockList " + i + " parts is " + self.globalWriteBlockList[i].parts + " offset is " + self.globalWriteBlockList[i].offset + " MBR is " + maxByteRequest);
self.globalWriteBlockList[i].requestReference = [];
// If we're optimized...
for (var j = 0; j < self.globalWriteBlockList[i].parts; j++) {
requestList[thisRequest] = self.globalWriteBlockList[i].clone();
self.globalWriteBlockList[i].requestReference.push(requestList[thisRequest]);
requestList[thisRequest].offset = startByte;
requestList[thisRequest].byteLength = Math.min(maxByteRequest, remainingLength);
requestList[thisRequest].byteLengthWithFill = requestList[thisRequest].byteLength;
if (requestList[thisRequest].byteLengthWithFill % 2) { requestList[thisRequest].byteLengthWithFill += 1; }
// max
requestList[thisRequest].writeBuffer = self.globalWriteBlockList[i].writeBuffer.slice(lengthOffset, lengthOffset + requestList[thisRequest].byteLengthWithFill);
requestList[thisRequest].writeQualityBuffer = self.globalWriteBlockList[i].writeQualityBuffer.slice(lengthOffset, lengthOffset + requestList[thisRequest].byteLengthWithFill);
lengthOffset += self.globalWriteBlockList[i].requestReference[j].byteLength;
if (self.globalWriteBlockList[i].parts > 1) {
requestList[thisRequest].datatype = 'BYTE';
requestList[thisRequest].dtypelen = 1;
requestList[thisRequest].arrayLength = requestList[thisRequest].byteLength;//self.globalReadBlockList[thisBlock].byteLength; (This line shouldn't be needed anymore - shouldn't matter)
}
remainingLength -= maxByteRequest;
thisRequest++;
startByte += maxByteRequest;
}
}
self.clearWritePacketTimeouts();
self.writePacketArray = [];
// outputLog("GWBL is " + self.globalWriteBlockList.length);
// Before we initialize the self.writePacketArray, we need to loop through all of them and clear timeouts.
// The packetizer...
while (requestNumber < requestList.length) {
// Set up the read packet
// Yes this is the same master sequence number shared with the read queue
var numItems = 0;
// Maybe this shouldn't really be here?
self.writeReqHeader.copy(self.writeReq, 0);
// Packet's length
var packetWriteLength = 10 + 4; // 10 byte header and 4 byte param header
self.writePacketArray.push(new S7Packet());
var thisPacketNumber = self.writePacketArray.length - 1;
self.writePacketArray[thisPacketNumber].seqNum = self.getNextSeqNum();
// outputLog("Write Sequence Number is " + self.writePacketArray[thisPacketNumber].seqNum);
self.writePacketArray[thisPacketNumber].itemList = []; // Initialize as array.
for (i = requestNumber; i < requestList.length; i++) {
//outputLog("Number is " + (requestList[i].byteLengthWithFill + 4 + packetReplyLength));
if (requestList[i].byteLengthWithFill + 12 + 4 + packetWriteLength > self.maxPDU) { // 12 byte header for each item and 4 bytes for the data header
if (numItems === 0) {
outputLog("breaking when we shouldn't, byte length with fill is " + requestList[i].byteLengthWithFill + " max byte request " + maxByteRequest, 0, self.connectionID);
throw new Error("Somehow write request didn't split properly - exiting. Report this as a bug.");
}
break; // We can't fit this packet in here.
}
requestNumber++;
numItems++;
packetWriteLength += (requestList[i].byteLengthWithFill + 12 + 4); // Don't forget each request has a 12 byte header as well.
self.writePacketArray[thisPacketNumber].itemList.push(requestList[i]);
}
}
}