HMI communication

ajack · **Joined:** Wed Feb 22, 2012 12:01 am **Posts:** 31

Hi,
My system requires transceiver to communicate HMI (iX Panel T10A) and Omron PLC using Host Link protocol. Although I read through all PLC’s datasheet and iX user guide, I still got some unclear points about communication:
1. Basically, TXD or RXD function block in PLC would determine which register to be sent and vice versa. So, what’s the point in choosing controller’s register in Tags menu?
2. Writing bits from HMI to controller requires 3 steps (reading word from controller, set/reset bit, send back to controller). Would it be really slow if there are about 10 bits (on/off button) to be set/reset? In order to reduce time consumption for those processes, I would use internal tags for all the button and set bit in data register and send back just 1 word back to controller.
3. I just use particular registers from controller in particular screens. But, does that mean I have to transmit and receive all registers throughout the process?
Thanks and best regards,
Phong Duong

Ron L. · **Joined:** Fri Jul 15, 2011 3:21 pm **Posts:** 215

1. I'm not sure what you mean. Are you referring to setting the address?

The driver includes a way to import a tag list from a .CSV file, but nothing beyond that has been developed for that driver.

2. Yes, if you need all of those bits set immediately, you would be better off doing that by writing one word to the PLC rather than bit by bit.

3. If a tag is being displayed, it will be polled. If it is not being displayed, it is not polled. However, if "Always Active" is checked, then the tag will poll all the time.

ajack · **Joined:** Wed Feb 22, 2012 12:01 am **Posts:** 31

Hi Ron,

Thanks for your answer!

1. Addressing register is what I want to talk about. Does iX device has a built in driver so that it can transceive data back and forth with PLC device. In this case, we do not need any TXD and RXD function block in PLC to communicate, do we? Cause the iX's driver will handle all the rest.

2. I think I should use just 1 word to handle all bit by bit manipulation.

3. I'm totally got it, thanks for your help!

Best regards,

Phong Duong

ajack · **Joined:** Wed Feb 22, 2012 12:01 am **Posts:** 31

Hi Ron,

I did what as what said, and it actually transmit data from HMI to PLC, but the problem is very slow response!

I did bit manipulation and update Data (which connect to PLC) every 500ms.

Here is my code:

Code:

    public partial class Transceiver
   {
      private static Timer timer = null;
      
      static Transceiver()
      {
         timer = new Timer();
         timer.Tick += new EventHandler(TimeOut);
         timer.Interval = 500;
      }

      public static void Stop() 
      {
         try
         {
            timer.Enabled = false;
         }
         catch(Exception) {}
      }
      
      public static void Start()
      {
         try
         {
            timer.Enabled = true;
         }
         catch(Exception) {}
      }
      
      private static void TimeOut(Object myObject, EventArgs myEventArgs) 
      {
         //DATA tag is connect to PLC
         Globals.Tags.DATA.Value = Globals.Tags.temp.Value;
         // this is just for timer inspection
         Globals.Tags.timer.Value++;
      }      
    }

Ron L. · **Joined:** Fri Jul 15, 2011 3:21 pm **Posts:** 215

When I opened your project, for some reason the PollGroup column wasn't set, so I'm not sure what poll-rate you are using.

You may want to try raising the communication baud rate from 9600 and see if that helps.

Make sure that you have the latest release iX Developer 1.31.93.

ajack · **Joined:** Wed Feb 22, 2012 12:01 am **Posts:** 31

Dear Ron,

I don't think this problems caused by older version (I'm using iX 1.30).
When you open Tags menu, make sure to check Other Columns and you will find Poll Groups, it show that I already choose Polling Rate for the driver.

Thanks,

Phong Duong