From 42b551fe4e60e15c69608278b811b48e3fe179bf Mon Sep 17 00:00:00 2001
From: Eric Leong <leong@cooper.edu>
Date: Wed, 17 Apr 2013 22:46:38 -0400
Subject: [PATCH] Support for 'read holding registers'.

---
 client.js | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/client.js b/client.js
index be63b56..855d5c2 100644
--- a/client.js
+++ b/client.js
@@ -58,6 +58,18 @@ Client.REQUESTS = {
 };
 
 Client.RESPONSES = {
+  // READ_HOLDING_REGISTERS
+  3: function(bufferlist) {
+    var rtn = [];
+    var binary = Binary(bufferlist)
+      .getWord8('byteLength').end();
+    rtn.byteLength = binary.vars.byteLength;
+    for (var i=0, l=binary.vars.byteLength/2; i<l; i++) {
+      binary.getWord16be("val");
+      rtn.push(binary.end().vars.val);
+    }
+    return rtn;
+  },
   // READ_INPUT_REGISTERS
   4: function(bufferlist) {
     var rtn = [];