TCP Driver - Writing string commands and receiving responses

Ignition
1

Wanted to check my understanding of the TCP/UDP driver and if I am using it correctly for the intended function of writing a TCP command and reading back a response.

I have a tester device that I can connect at a specified tcp port (using either a vendor supplied application, or using Putty with the connection type set to "Raw"), and I am successfully able to send a text command to the device and receive the response back.

I am trying to do this with the TCP driver (Ignition v8.1.17, TCP driver v6.1.17), and it appears that the OPC device shows as connected at the same IP/port, but doesn't appear to give me the expected response back (0 or 1 in this case) when writing my command to the Writable tag (writeback is enabled).

When I did type in the READY? command to the Writable tag, I did see the remote-control light on the device come on, so it seems that some message did in fact get to the device. But not sure if it could be an issue of my string not being formatted correctly in some way (in Putty I'm typing it exactly as seen, as READY?), or if I'm understanding correctly that the response back should arrive back in the Message tag?

I also did see a number of threads mentioning scripting with various Java / Jython socket libraries, I can go down that route if needed - But I wanted a sanity check first, if what I'm doing should be able to be done directly with the TCP driver.

Thank you for the help,

tcp_tags

2

The TCP/UDP drivers are meant to communicate with things like barcode scanners and scales that send back predictable messages that are either a fixed length or have frames delimited by some marker character.

So it really depends on the response format of whatever it is you're talking to, and whether or not you can configure the driver to reliably receive the responses from it. That "Packet Based" is even an option for the message delimiter when configuring a TCP device is a haunting mistake from a decade+ ago - it's complete nonsense for TCP.

3

Gotcha, thanks Kevin, I'll check on a solution through scripting.