fixes WRITE_MULTIPLE_COILS missing "number of bytes to follow" field

dresende · Feb 10, 2016 · 8e04035 · 8e04035
1 parent db973a4
commit 8e04035
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Showing 2 changed files with 5 additions and 3 deletions.
diff --git a/lib/Server/ReadStream.js b/lib/Server/ReadStream.js
@@ -74,7 +74,8 @@ ReadStream.prototype._transform = function (chunk, encoding, next) {
 				pkg.from   = data.readUInt16BE(0);
 				pkg.to     = data.readUInt16BE(2) + pkg.from - 1;
 				pkg.items  = [];
-				for (var i = 4; i < data.length; i++) {
+
+				for (var i = 5; i < data.length; i++) {
 					for (var j = 0; j < 8; j++) {
 						pkg.items.push((data[i] >> j) & 0x1);
 						if (pkg.items.length >= pkg.to - pkg.from + 1) {

diff --git a/lib/protocol/WRITE_MULTIPLE_COILS.js b/lib/protocol/WRITE_MULTIPLE_COILS.js
@@ -4,11 +4,12 @@ var pack     = require("./tools").pack2uint16;
 
 exports.request = function (transactionId, unitId, startAddress, endAddress, status) {
 	var bits = packbits(status);
-	var buf = new Buffer(bits.length + 4);
+	var buf = new Buffer(bits.length + 5);
 
 	buf.writeUInt16BE(startAddress, 0);
 	buf.writeUInt16BE(endAddress - startAddress + 1, 2);
-	bits.copy(buf, 4);
+	buf.writeUInt8(Math.ceil((endAddress - startAddress + 1) / 8), 4);
+	bits.copy(buf, 5);
 
 	return new Package(
 		transactionId,