I have noticed that it takes about 100ms before a message sent by the device is matched on the element. The response does not have a trailer, but the third and fourth byte contain the size of the payload, so the driver uses:

communicationOptions="makeCommandByProtocol;packetInfo:2,2,false"

 As the size of the response is known, there shouldn't be any significant delay.

The following parameters make up the response:

<Param id="2">
   <Name>IpHeader</Name>
   <Description>IP Header</Description>
   <Type>fixed</Type>
   <Interprete>
      <RawType>other</RawType>
      <Type>string</Type>
      <LengthType>fixed</LengthType>
      <Length>2</Length>
      <Value>0x000x0C</Value>
   </Interprete>
</Param>

<Param id="3">
   <Name>CommandLength</Name>
   <Description>CommandLength</Description>
   <Type>length</Type>
   <Interprete>
      <RawType>unsigned number</RawType>
      <Type>double</Type>
      <LengthType>fixed</LengthType>
      <Length>2</Length>
      <Endian>big</Endian>
   </Interprete>
   <Length>
      <Content>
         <Param>2</Param>
      </Content>
   </Length>
</Param>

<Param id="5">
   <Name>Response</Name>
   <Description>Response</Description>
   <Type>read</Type>
   <Interprete>
      <RawType>other</RawType>
      <Type>string</Type>
      <LengthType id="3">other param</LengthType>
   </Interprete>
</Param>

100ms doesn't sound like much, but the device does not support any bulk commands, so this 100ms adds up quickly when I need to retrieve data for over 1000 parameters.

I created a small driver and console application as tcp server to reproduce the result. The element and console application ran on the same server to eliminate network latency and system clock differences.

These are log lines from the application and element respectively:

2022/01/06 11:51:11.601 Send: Packet 3

2022/01/06 11:51:11.700|SLProtocol - 9816 - latencyTest|22476|CParameter::MatchParameter|DBG|2|-> Response new data (Packet 3)
   000000  5061636B65 742033                            Packet 3

What could reduce this delay?