Advanced General Purpose Output (GPO) [VIDEO]

Have you ever wanted a way to easily program indicators, such as a stack light, to notify when the Speedway Revolution reader has lost Ethernet connection, is inventorying tags and/or reading tags, or is even functioning (perhaps power unplugged)? How about setting a pulsed duration of the GPO event (i.e. reading and/or encoding tags on a conveyor belt)?

If so, then Advanced GPO functionality is what you are looking for!

You can control the advanced GPO feature of Speedway Revolution readers using this custom parameter.

• When set to Normal (default) the GPO is set via the regular LLRP SET_READER_CONFIG message.
• When set to Pulsed, the GPO changes state based on the SET_READER_CONFIG message, and will change to the opposite state after GPOPulseDurationMSec milliseconds. 
• When set to "Reader_Operational_Status‟, "LLRP_Connection_Status", "Reader_Inventory_Status‟, "Network_Connection_Status‟ or "Reader_Inventory_Tags_Status‟ the GPO status acts like a Boolean value.
• When high (true, 1), the corresponding status is true, meaning the reader is operating, has a LLRP connection, is inventorying, has a network connection or tags are being singulated (respectively). 
• When low (false, 0), the opposite is the case.

The following code sample shows how to configure advanced GPO using the LLRP Toolkit (LTK). The method below creates a SET_READER_CONFIG message on the reader that allows for "Reader_Operational_Status‟, "LLRP_Connection_Status", "Reader_Inventory_Status‟, "Network_Connection_Status‟ or "Reader_Inventory_Tags_Status‟ property to be enabled.

Be sure to send the message: msg.AddCustomParameter(GPO) and to do error checking/handling using MSG_SET_READER_CONFIG_RESPONSE.

private void button4_Click(object sender, EventArgs e)
{
if (btnOpen.Text == "Close")
{
 
MSG_SET_READER_CONFIG msg = new MSG_SET_READER_CONFIG();
 
PARAM_ImpinjAdvancedGPOConfiguration GPO = new PARAM_ImpinjAdvancedGPOConfiguration();
GPO.GPOPortNum = 1;
GPO.GPOMode = new ENUM_ImpinjAdvancedGPOMode();
if (rbNormal.Checked == true)
{
GPO.GPOMode = ENUM_ImpinjAdvancedGPOMode.Normal;
}
else if (rbLLRP.Checked == true)
{
GPO.GPOMode = ENUM_ImpinjAdvancedGPOMode.LLRP_Connection_Status;
}
else if (rbPulsed.Checked == true)
{
GPO.GPOMode = ENUM_ImpinjAdvancedGPOMode.Pulsed;
GPO.GPOPulseDurationMSec = 2000;
}
else if (rbInventory.Checked == true)
{
GPO.GPOMode = ENUM_ImpinjAdvancedGPOMode.Reader_Inventory_Status;
}
else if (rbOperatioinal.Checked == true)
{
GPO.GPOMode = ENUM_ImpinjAdvancedGPOMode.Reader_Operational_Status;
}
 
else if (rbITS.Checked == true)
{
GPO.GPOMode = ENUM_ImpinjAdvancedGPOMode.Reader_Inventory_Tags_Status;
}
else if (rbNCS.Checked == true)
{
GPO.GPOMode = ENUM_ImpinjAdvancedGPOMode.Network_Connection_Status;
}
else MessageBox.Show("Error setting GPO Mode");
 
 
msg.AddCustomParameter(GPO);
 
MSG_SET_READER_CONFIG_RESPONSE rsp = reader.SET_READER_CONFIG(msg, out msg_err, 12000);
 
if (rsp != null)
{
textBox2.Text = rsp.ToString();
}
else if (msg_err != null)
{
textBox2.Text = rsp.ToString();
}
else
textBox2.Text = "Commmand time out!";
}
else MessageBox.Show("Please Open Reader and continue");
 
}

If you are using Java here is some XML and java code that will pulse GPO 1.  Also, please note that the XML SET_READER_CONFIG portion could be used by C, C#, or C++. 

• First send the following XML to configure the reader:

<?xml version="1.0"?>
<SET_READER_CONFIG MessageID="0" xmlns:Impinj="http://developer.impinj.com/ltk/schema/encoding/xml/1.18"
xmlns="http://www.llrp.org/ltk/schema/core/encoding/xml/1.0">
 <ResetToFactoryDefault>false</ResetToFactoryDefault>
 <ImpinjAdvancedGPOConfiguration xmlns="http://developer.impinj.com/ltk/schema/encoding/xml/1.18">
  <GPOPortNum>1</GPOPortNum>
  <GPOMode>Pulsed</GPOMode>
  <GPOPulseDurationMSec>2000</GPOPulseDurationMSec>
  </ImpinjAdvancedGPOConfiguration>
</SET_READER_CONFIG>

• Use the following java to pulse the GPO 1:

SET_READER_CONFIG msg = new SET_READER_CONFIG();
GPOWriteData GPOWriteData = new GPOWriteData();
GPOWriteData.setGPOData(new Bit(true));
GPOWriteData.setGPOPortNumber(new UnsignedShort(1));
msg.addToGPOWriteDataList(GPOWriteData);
msg.setMessageID(getUniqueMessageID());
msg.setResetToFactoryDefault(new Bit(false)); 
LLRPMessage response = connection.transact(msg, 12000);

Here is a video showing Advanced GPO in action!