In many smaller switching tasks it is not worth the effort to create special application software or purchase expensive automation tools. Here it’s enough to initiate the desired switching operation by simply clicking on an incon or entering a command. By using the Web-IO Digital and short VBScripts you can implement such solutions with just a few lines of commands.
VBScript is an easy-to-program interpreter language supported by Windows 2000, XP and Vista. As the name (Visual Basic Script) implies, the syntax of VBScript is derived from Visual Basic. No special development environment is required to create VBScripts - all you need is a text editor. We recommend the free PSPAD editor (www.pspad.com), which has syntax coloring for VBScript. When saving VBScripts the file extension ".vbs" is used.
The examples below show how VBScript and the Web-IO interact.
You don’t have a Web-IO® yet but would like to try the example out sometime?
No problem: We will be glad to send you the Web-IO Digital 2xInput, 2xOutput at no charge for 30 days. Simply fill out a sample ordering form, and we will ship the Web-IO for testing on an open invoice. If you return the unit within 30 days, we will simply mark the invoice as paid.
assigned it an IP address - which with WuTility is no problem.
1. Set an output using VBScript
When the following script is invoked, Output 0 on the Web-IO having IP address 10.40.22.101 is set.
' VB Script
Document option explicit
Dim objHttp Set objHttp = WScript.CreateObject("WinHttp.WinHttpRequest.5.1") If objHttp Is Nothing Then Set objHttp = WScript.CreateObject("WinHttp.WinHttpRequest")
objHttp.Option(4) = 256 + 512 + 4096 + 8192
objHttp.SetTimeouts 0, 5000, 10000, 10000
objHttp.Open "GET", "http://10.40.22.101/outputaccess0?PW=&State=ON&",
FALSE
objHttp.setRequestHeader "User-Agent",
WScript.ScriptName
objHttp.Send "" If Not (objHttp.statusText = "OK")
Then
WScript.Echo "Error: "
& objHttp.statusText
WScript.Quit 1 Else
WScript.Echo objHttp.ResponseText End If
The core of this script is the WinHttp object, which is used to send commands to the Web-IO. The actual command is passed using objHttp.Open.
http://10.40.22.101/outputaccess0?PW=&State=ON& specifies that Output 0 on Web-IO 10.40.22.101 is to assume the ON state
objHttp.ResponseText reads in the response from the Web-IO. For command outputaccess the Web-IO returns a string consisting of the word output, a semicolon and the output status.
Example output;1
A detailed description of the possible Web-IO commands can be found in the manual for the Web-IO starting on page 102.
2. Invoking VBScripts from batch jobs
Batch jobs under Windows were originally intended for automatically running Windows commands. A classic example is the Autoexec.bat in older DOS environments. A list of commands is entered in the batch file which are processed sequentially when the list is opened.
In Windows systems this means you can automate scripts and the opening of programs. If for example you want to switch outputs on different Web-IOs with a call, this can also be done using a batch job.
The corresponding names of the VBScripts need to be written below each other in the batch file. In the case of scripts like the one above, you need to create a separate script for each switching operation.
This is why in batch jobs it makes more sense to create a universally usable script which when it is invoked is told using additional parameters what the switching task consists of. In the following VBScript you can pass these parameters to it when invoked:
IP
:
IP address of the Web-IO
PORT
:
TCP port of the Web-IO This parameter is optional; if it is not transmitted, the script uses Port 80
PW
:
Administrator or operator password for the Web-IO This parameter is optional; if it is not transmitted, the script runs without a password
MASK
:
indicates in hex format which outputs are supposed to be set This parameter is optional; if it is not transmitted, the script runs using all outputs
STATE
:
indicates in hex format to which state the outputs are supposed to be set
Dim objArgs, strArg, strArgall Dim IP, PORT, PASSWORD, MASK, STATE, URLStr Dim objHttp Set objArgs = WScript.Arguments
'# Make sure that script starts as console
application (best way "cscript //h:cscript") Dim WshShell : Set WshShell = WScript.CreateObject("WScript.Shell") If Right(WScript.FullName, Len(WScript.Fullname) - Len(WScript.Path)
-1) _
= "WScript.exe"
Then For each strArg in objArgs
strArgall = strArgall & "
" & strArg next
WshShell.Run "cmd /k cscript
" & Chr(34) & WScript.ScriptFullName
_
& Chr(34) & strArgall
WScript.Quit EndIf
'# Check if there are Parameters If WScript.Arguments.count < 1 Then
WScript.Echo "***********************************"
WScript.Echo "* Not enough
arguments *"
WScript.Echo "***********************************"
WScript.Echo ""
WScript.Echo "Syntyx: setoutput.vbs
IP=<IP address> [PORT=<portno.>] _
[PASSWORD=<password>] [MASK=<hex value>] STATE=<hex
value>"
WScript.Quit End If
'# Read the Parameters
for each strArg in objArgs IfLeft(strArg,3) = "IP="
then
IP = Mid(strArg, 4, Len(strArg)
- 3) End If
If Left(strArg,5) = "PORT="
then
PORT = Mid(strArg, 6, Len(strArg)
- 5) End If
If Left(strArg,9) = "PASSWORD="
then
PASSWORD = Mid(strArg, 10, Len(strArg)
- 9) End If
If Left(strArg,5) = "MASK="
then
MASK = Mid(strArg, 6, Len(strArg)
- 5) End If
If Left(strArg,6) = "STATE="
then
STATE = Mid(strArg, 7, Len(strArg)
- 6) End If Next
'# Mount the command String If IP <> ""
then
URLStr = "http://"
& IP else
WScript.Echo "***********************************"
WScript.Echo "* Not
enough arguments : IP *"
WScript.Echo "***********************************" End If
If PORT <> ""
then
URLStr = URLStr & ":"
& PORT End If
If MASK <> ""
then
URLStr = URLStr & "Mask="
& MASK & "&" End If
If STATE <> "" then
URLStr = URLStr & "State="
& STATE & "&" else
WScript.Echo "***********************************"
WScript.Echo "* Not
enough arguments : STATE *"
WScript.Echo "***********************************" End If
'# Send the Command String via HTTP object
Set objHttp = WScript.CreateObject("WinHttp.WinHttpRequest.5.1") If objHttp Is Nothing Then Set objHttp = WScript.CreateObject("WinHttp.WinHttpRequest")
objHttp.Option(4) = 256 + 512 + 4096 + 8192
objHttp.SetTimeouts 0, 5000, 10000, 10000
objHttp.Open "GET", URLStr,
FALSE
objHttp.setRequestHeader "User-Agent",
WScript.ScriptName
objHttp.Send "" If Not (objHttp.statusText = "OK")
Then
WScript.Echo "Error: "
& objHttp.statusText
WScript.Quit 1 else
WScript.Echo objHttp.ResponseText End If
After the selected action has been performed, the script returns the status of the outputs.
e.g. output:0100
The status message consists of the word output, a semicolon and the output status in hex format.
TIP: The Windows Script Host (WSH) is responsible for running VBScripts; WSH is present in two variants on every Windows PC. The variants Wscript and Cscript differ mainly in how the data are output. Unless otherwise configured, the scripts are processed using Wscript, and text messages are output in a Windows dialog box. The disadvantage to this is that the user has to acknowledge each message in order for the script to continue. This type of processing is undesirable for use in batch jobs.
By entering the command wscrit //H:cscript, Cscript is defined as the standard Script Host. Cscript returns all messages in a DOSBOX and does not wait for confirmation.
The script shown above checks which Script Host is active, cancels if Wscript is active and restarts using Cscript.
Still, to ensure that the script can run faster, it is recommended that you switch to Cscript from the outset.
Additional programming examples for socket programming can be found on the Tool pages for the Web-IO. A detailed description for the socket interface of the Web-IO Digital models can be found in the reference manual.
