Comms Script to Trigger Read and Read X-number of Codes by Sending a Single Number

Solution: controlling the number of read codes via RS-232 input

Problem description

Some applications require external control over how many Data Matrix codes a DataMan reader should read per trigger event. For example, a PLC or host system may need to dynamically switch between reading one code or multiple codes based on process state.

Solution overview

This solution uses a communication script to monitor the RS-232 (COM1) interface of the DataMan reader.
Based on simple ASCII commands received over RS-232 ("1" or "2"), the script adjusts the Multi-Code configuration and triggers a read accordingly.

Solution script

function CommHandler()
{
   return {
       onConnect: function (peerName)
       {
           my_name = peerName;
           if (my_name != "COM1")
               return false;

           this.send(my_name + ": connected\r\n");
           return true;
       },

 onDisconnect: function ()
       {
       },

       onError: function (errorMsg)
       {
       },

       onExpectedData: function (inputString)
       {
           if (inputString == "1") {
               dmccSet("MULTICODE.NUM-CODES", 1);
               dmccCommand("TRIGGER", true);
           }

 else if (inputString == "2") {
               dmccSet("MULTICODE.NUM-CODES", 2);
               dmccSet("MULTICODE.MAX-NUM-CODES", 2);
               dmccCommand("TRIGGER", true);
           }
           return true;
       },

       onUnexpectedData: function (inputString)
       {
           return true;
       },

       onTimer: function ()
       {
       },

       onEncoder: function ()

   {
       }
   };
}

How it works

• The script listens for incoming data on COM1 (RS-232).
• When a command is received:
  • "1" → Configure the reader to read one Data Matrix code
  • "2" → Configure the reader to read two Data Matrix codes
• After configuration, a software trigger is issued.
• The Multi-Code settings are updated dynamically before each trigger.

Configuration notes

• Ensure RS-232 communication parameters (baud rate, parity, stop bits) match the host system.
• The input commands are case-sensitive and must exactly match "1" or "2".
• This approach can be extended to support additional commands (e.g., "3", "4") if required.

Summary

• RS-232 input can be used to dynamically control Multi-Code behavior.
• Simple ASCII commands allow flexible runtime configuration.
• This method is well suited for PLC- or host-controlled reading scenarios.