# TCP device driver connection issues

**URL:** <https://forum.inductiveautomation.com/t/tcp-device-driver-connection-issues/17373>\
**Category:** Ignition\
**Tags:** ignition78\
**Created:** [March 15, 2018, 10:10am UTC](https://forum.inductiveautomation.com/t/tcp-device-driver-connection-issues/17373 "2018-03-15T10:10:15Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![Transistor](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/transistor/32/3380_2.png) [@Transistor](https://forum.inductiveautomation.com/u/Transistor)\
**Post date:** [March 15, 2018, 10:10am UTC](https://forum.inductiveautomation.com/t/tcp-device-driver-connection-issues/17373/1 "2018-03-15T10:10:15Z")

</div>

I have configured the TCP driver to monitor a checkweigher which spits out a data string at 3 s intervals when running. The connection status keeps changing from Good to Not Connected.

In an attempt to debug the comms I created a _DebugString_ tag in my UDT. I can write to this in the _TCPDataString_ value changed event as follows:

> system.tag.write("[.]DebugString", "TCP value changed! " + currentValue.value[22:30] )  
> if currentValue.quality.isGood():  
> system.tag.write("[.]DebugString", "TCP value is good @ " + currentValue.value[22:30] )  
> if currentValue.value != system.tag.read("[.]\_FilteredDataString"):  
> else:  
> system.tag.write("[.]DebugString", "TCP value is NOT good @ " + currentValue.value[22:30] )

![](https://us1.discourse-cdn.com/inductiveautomation/original/2X/2/27faec23822d8f530391e37756280973d8ca99eb.gif)

_Figure 1. Watch the DebugString. Every 20 s or so it reports a random number. (The animation is 20 s long and there is one occurrence of the string '7'.)_

**Questions**

1. Where is the '7' coming from? There is nothing else writing to that tag.
2. Why is my connection dropping off?

 ![](https://us1.discourse-cdn.com/inductiveautomation/original/2X/7/78baa0ee990de13dd232de789b96324ef371476d.png)

_Figure 2. TCP device configuration._

![](https://us1.discourse-cdn.com/inductiveautomation/original/2X/3/38d1afbb1b234b0c4cacb4f082e630e102725835.png)

_Figure 3. Console report._