How to write to Kepware IoT gateway tags using Axiom

•  The first step is to setup Kepware with IoT Gateway.

Kepware IoT Gateway requires a 32 bit Java JRE

• Next, configure a rest server agent in Kepware IoT Gateway configuration.

• After this has been completed add the desired tags to the IoT Gateway agent.

• After the tags have been added, create a new axiom application.
• Add a button and name it btnSetTagValue.

• Click on the button in Axiom and click on the click event handler in the properties. This will load the scripting dialog.

• Copy and paste this code into Axiom

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Collections;
using AxiomCore;
using System.Security.Cryptography.X509Certificates;
using System.Net.Security;
using System.Net;

namespace AxiomScripts
{
 public partial class Screen1_Script
 {
 protected override void OnScreenVisible()
 {
 
 }
 
 protected override void OnScreenInvisible()
 {
 
 }
 
 public void btnSetTagValue_Click(object sender, EventArgs e)
 {
 // insert code here
 WriteTagValue(tagToWriteTo, valueToWrite);
 }

 // kepware iotgateway write endpoint
 private string KepwareWriteEndpoint = "https://localhost:39320/iotgateway/write";
 // tag to write to
 string tagToWriteTo = "Data Type Examples.16 Bit Device.K Registers.Boolean1";
 // value to write to the tag
 int valueToWrite = 1;
 
 public void WriteTagValue(string tagName, int val)
 {
 // build the json to send to kewpare
 string postData = "[{\"id\": \"" + tagName + "\", \"v\":" + val + "}]";
 string response;
 
 try
 {
 HttpWebRequest request = (HttpWebRequest)WebRequest.Create(KepwareWriteEndpoint);
 request.Method = "POST";
 request.ServerCertificateValidationCallback += remoteCertificateValidationCallback;
 request.ContentType = "application/json";

 byte[] post = System.Text.Encoding.UTF8.GetBytes(postData);
 using (Stream rs = request.GetRequestStream())
 {
 rs.Write(post, 0, post.Length);
 }

 using (StreamReader sr = new StreamReader(request.GetResponse().GetResponseStream()))
 {
 response = sr.ReadToEnd();
 }
 
 lblSuccess.Text = "Success";
 }
 catch (Exception ex)
 {
 lblSuccess.Text = "Failed to write tag value: " + ex.ToString();
 }
 }
 
 private bool remoteCertificateValidationCallback(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
 {
 // does not perform any certificate validation to permit self signed certificates using https
 // Note: for development localhost purposes only
 return true;
 }
 }
}

• Ensure the URL configured in Kepware IoT rest server agent matches the domain in the KepwareWriteEndpoint setting above.
• Configure the tagToWriteTo variable to be the tag you want to write to.
• Configure the value you want to write.
• Close the scripting dialog.
• Add a label to the screen named lblSuccess.
• Save the application and test.