Initial commit

lib/jsmodbus/handler/server/WriteMultipleRegisters.js

@@ -0,0 +1,60 @@
+'use strict';
+
+const Stampit = require('stampit');
+const Put     = require('put');
+
+module.exports = Stampit()
+    .init(function () {
+        const FC = 16;
+        let init = () => {
+            this.log.debug('initiating write multiple registers request handler.');
+            this.responseDelay = this.responseDelay || 0;
+            this.setRequestHandler(FC, onRequest);
+        };
+    
+        let _onRequest = (pdu, cb) => {
+            if (pdu.length < 3) {
+                cb(Put().word8(0x90).word8(0x02).buffer());
+            } else {
+                // const fc          = pdu.readUInt8(0);
+                const start       = pdu.readUInt16BE(1);
+                const byteStart   = start * 2;
+                const quantity    = pdu.readUInt16BE(3);
+                const byteCount   = pdu.readUInt8(5);
+
+                if (quantity > 0x007b) {
+                    cb(Put().word8(0x90).word8(0x03).buffer());
+                } else {
+                    this.emit('preWriteMultipleRegistersRequest', byteStart, quantity, byteCount);
+
+                    let mem = this.getHolding();
+
+                    if (!quantity || byteStart + (quantity * 2) > mem.length) {
+                        cb(Put().word8(0x90).word8(0x02).buffer());
+                    } else {
+                        let response = Put().word8(0x10).word16be(start).word16be(quantity).buffer();
+                        let j = 0;
+
+                        for (let i = byteStart; i < byteStart + byteCount; i += 1) {
+                            mem.writeUInt8(pdu.readUInt8(6 + j), i);
+                            j++;
+                        }
+
+                        this.emit('postWriteMultipleRegistersRequest', byteStart, quantity, byteCount);
+
+                        cb(response);
+                    }
+                }
+            }
+        };
+
+        let onRequest = (pdu, cb) => {
+            if (this.responseDelay) {
+                setTimeout(_onRequest, this.responseDelay, pdu, cb);
+            } else {
+                setImmediate(_onRequest, pdu, cb);
+            }
+        };
+
+        init();
+    });