diff --git a/Equipment/prologix_connect.m b/Equipment/prologix_connect.m
index eb47c0e..b3080ff 100644
--- a/Equipment/prologix_connect.m
+++ b/Equipment/prologix_connect.m
@@ -1,19 +1,32 @@
-function [ t,version ] = prologix_connect(ipAddress,port)
-%PROLOGIX_CONNECT open TCP/IP connection with Prologix Ethernet GPIB
-%converter
-%   Detailed explanation goes here
-    if nargin < 2
-        port = 1234;
-        if nargin < 1
-            ipAddress = '10.0.0.2';
-        end
+function [ t,version ] = prologix_connect(ipAddress)
+%PROLOGIX_CONNECT opens TCP/IP connection with Prologix device
+%   [t,version] = PROLOGIX_CONNECT() will automaticly find IP 
+%   address and starts connection.
+%   [t,version] = PROLOGIX_CONNECT(ipAddress) starts connection
+%   with given IP address.
+%   IP address is autodiscovered. But can be used for a
+%   device on a different subnet.
+%   If you don't know the IP address leave it empty.
+    
+%% define variables
+    port = 1234;
+    % if no IP address is given start autodiscovery;
+    if nargin < 1
+        ipAddress = prologix_discovery();
+    elseif isempty(regexp(ipAddress,'([1-2]?[0-9]{1,2}\.){3}[1-2]?[0-9]{1,2}','match'))
+        error('Given IP address is not valid, leave empty to use autodiscovery of device');
     end
-    echotcpip('on', port);
-    t = tcpip(ipAddress,port);
-    fopen(t);
-    fprintf(t, '++mode 1');
-    fprintf(t, '++auto 0');
-    fprintf(t, '++ver');
-    version = ['Firmware Version: ', fscanf(t)];
+        
+    
+%% open connection.
+    echotcpip('on', port);      % start listening for tcp packets on port
+    t = tcpip(ipAddress,port);  % define tcpip connection
+    fopen(t);                   % open connection
+
+%% configure prologix.
+    fprintf(t, '++mode 1');     %set device in controller mode
+    fprintf(t, '++auto 0');     %disable automatic datapull. this avoids errors on equipment.
+    fprintf(t, '++ver');        %ask firmware version of the prologix.
+    version = ['Firmware Version: ', fscanf(t)]; %pull firmware function from prologix.
 end