Add String16

package.json

@@ -1,6 +1,6 @@
 {
   "name": "s7client",
-  "version": "1.1.0",
+  "version": "1.1.5",
   "description": "Hi level API for node-snap7 to communication with Siemens S7 PLCs",
   "homepage": "https://psi-4ward.github.io/s7client",
   "main": "src/index.js",

src/datatypes.js

@@ -47,13 +47,13 @@ const Datatypes = {
    * WORD
    * @type {S7ClientDatatype}
    */
-  WORD: _gen(2, 'UInt16BE', snap7.S7WLWord),
+  WORD: _gen(2, 'UInt16BE', snap7.S7WLByte),
 
   /**
    * DWORD
    * @type {S7ClientDatatype}
    */
-  DWORD: _gen(4, 'UInt32BE', snap7.S7WLDWord),
+  DWORD: _gen(4, 'UInt32BE', snap7.S7WLByte),
 
   /**
    * CHAR
@@ -65,24 +65,70 @@ const Datatypes = {
     formatter: v => Buffer.from(v, 'ascii'),
     S7WordLen: snap7.S7WLByte
   },
+
+  /**
+   * STRING16
+   * @type {S7ClientDatatype}
+   */
+   STRING16: { // type to read an entire String[16] from PLC
+    bytes: 18,
+    parser: (buffer, offset = 0) => buffer.toString('ascii', offset + 2, buffer.readUInt8(1) + 2),
+    formatter: v => Buffer.concat([
+        Buffer.from([16, v.length <= 16 ? v.length : 16]),// maximum size | string size
+        Buffer.from(v.length <= 15 ? v : v.substring(0, 16), 'ascii'), // string to buffer
+        Buffer.from([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]) // fill zeros
+      ]).subarray(0, 18),
+    S7WordLen: snap7.S7WLByte
+  },
 
+
+  /**
+   * STRING15
+   * @type {S7ClientDatatype}
+   */
+   STRING15: { // type to read an entire String[15] from PLC
+    bytes: 18,
+    parser: (buffer, offset = 0) => buffer.toString('ascii', offset + 2, buffer.readUInt8(1) + 2),
+    formatter: v => Buffer.concat([
+        Buffer.from([15, v.length <= 15 ? v.length : 15]),// maximum size | string size
+        Buffer.from(v.length <= 15 ? v : v.substring(0, 15), 'ascii'), // string to buffer
+        Buffer.from([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]) // fill zeros
+      ]).subarray(0, 18),
+    S7WordLen: snap7.S7WLByte
+  },
+
+
+  /**
+   * STRING20
+   * @type {S7ClientDatatype}
+   */
+   STRING20: { // type to read an entire String[20] from PLC
+    bytes: 22,
+    parser: (buffer, offset = 0) => buffer.toString('ascii', offset + 2, buffer.readUInt8(1) + 2),
+    formatter: v => Buffer.concat([
+        Buffer.from([20, v.length <= 20 ? v.length : 20]),// maximum size | string size
+        Buffer.from(v.length <= 20 ? v : v.substring(0, 20), 'ascii'), // string to buffer
+        Buffer.from([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]) // fill zeros
+      ]).subarray(0, 22),
+    S7WordLen: snap7.S7WLByte
+  },
   /**
    * INT
    * @type {S7ClientDatatype}
    */
-  INT: _gen(2, 'Int16BE', snap7.S7WLWord),
+  INT: _gen(2, 'Int16BE', snap7.S7WLByte),
 
   /**
    * DINT
    * @type {S7ClientDatatype}
    */
-  DINT: _gen(4, 'Int32BE', snap7.S7WLDWord),
+  DINT: _gen(4, 'Int32BE', snap7.S7WLByte),
 
   /**
    * REAL
    * @type {S7ClientDatatype}
    */
-  REAL: _gen(4, 'FloatBE', snap7.S7WLReal),
+  REAL: _gen(4, 'FloatBE', snap7.S7WLByte),
 };
 
 module.exports = Datatypes;

src/index.js

@@ -227,7 +227,7 @@ class S7Client extends EventEmitter {
           WordLen: datatypes[v.type].S7WordLen,
           DBNumber: v.dbnr,
           Start: v.type === 'BOOL' ? v.start * 8 + v.bit : v.start,
-          Amount: 1
+          Amount: datatypes[v.type].bytes ? datatypes[v.type].bytes : 1, // changed to read size from type
         }
       });
 
@@ -264,7 +264,7 @@ class S7Client extends EventEmitter {
       WordLen: datatypes[v.type].S7WordLen,
       DBNumber: v.dbnr,
       Start: v.type === 'BOOL' ? v.start * 8 + v.bit : v.start,
-      Amount: 1,
+      Amount: datatypes[v.type].bytes ? datatypes[v.type].bytes : 1, // changed to read size from type
       Data: datatypes[v.type].formatter(v.value)
     }));