# Modbus TCP Read Timeout **URL:** \ **Category:** Ignition\ **Created:** [January 25, 2021, 3:37pm UTC](https://forum.inductiveautomation.com/t/modbus-tcp-read-timeout/42576 "2021-01-25T15:37:09Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![kumar.chellappan](https://avatars.discourse-cdn.com/v4/letter/k/2acd7d/32.png) [@kumar.chellappan](https://forum.inductiveautomation.com/u/kumar.chellappan)\ **Post date:** [January 25, 2021, 3:37pm UTC](https://forum.inductiveautomation.com/t/modbus-tcp-read-timeout/42576/1 "2021-01-25T15:37:10Z")
Hi, I am testing Modbus TCP. I am able to read and write without any issues but on the logs, it keeps on going into a read timeout. And the values in the tag browser goes in to bad\_stale. I have the force reconnect turned off as it constantly disconnects and reconnects. I have set up the modbus addressing for two holding registers. Could anyone point me in the right direction? Thank you. ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/d/4/d49d27730fe510298876b9f45d9857ea4fa462bc.png) ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [January 25, 2021, 3:57pm UTC](https://forum.inductiveautomation.com/t/modbus-tcp-read-timeout/42576/2 "2021-01-25T15:57:48Z")
It’s hard to tell if those are really the device not responding or possible caused by the frequent clock drifts you’re experiencing. Can you do a Wireshark capture to see if the device is responding or not? ---
**Author:** ![kumar.chellappan](https://avatars.discourse-cdn.com/v4/letter/k/2acd7d/32.png) [@kumar.chellappan](https://forum.inductiveautomation.com/u/kumar.chellappan)\ **Post date:** [January 25, 2021, 4:10pm UTC](https://forum.inductiveautomation.com/t/modbus-tcp-read-timeout/42576/3 "2021-01-25T16:10:49Z")
Yes. I did a Wireshark capture and I can see the read requests and response from the device. When I change the value of the tag, I can see the write request and the value changes on my PLC. ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [January 25, 2021, 4:12pm UTC](https://forum.inductiveautomation.com/t/modbus-tcp-read-timeout/42576/4 "2021-01-25T16:12:52Z")
Can you upload your logs and Wireshark capture somewhere so we can take a look? ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [January 25, 2021, 4:14pm UTC](https://forum.inductiveautomation.com/t/modbus-tcp-read-timeout/42576/5 "2021-01-25T16:14:01Z")
Those clock drift messages shouldn’t be ignored either. It means either your system clock is constantly changing or your server is overloaded and freezing for 7-8 seconds at a time, frequently. ---
**Author:** ![kumar.chellappan](https://avatars.discourse-cdn.com/v4/letter/k/2acd7d/32.png) [@kumar.chellappan](https://forum.inductiveautomation.com/u/kumar.chellappan)\ **Post date:** [January 25, 2021, 4:21pm UTC](https://forum.inductiveautomation.com/t/modbus-tcp-read-timeout/42576/6 "2021-01-25T16:21:14Z")
Yes. I have an ongoing issue (high CPU usage and high memory usage) and Technical support advised to do a java dump so they can check what is causing this. Is that the only way to go? Please see the attached link for the wireshark and igntion logs > **[Dropbox - File Deleted](https://www.dropbox.com/sh/kjrfsy9j8bh2jlz/AACNPZwP56YpD8IvhWKguK2va?dl=0)** > > Dropbox is a free service that lets you bring your photos, docs, and videos anywhere and share them easily. Never email yourself a file again! ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [January 25, 2021, 4:27pm UTC](https://forum.inductiveautomation.com/t/modbus-tcp-read-timeout/42576/7 "2021-01-25T16:27:08Z")
There’s no Modbus traffic in your capture 😕 ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [January 25, 2021, 4:43pm UTC](https://forum.inductiveautomation.com/t/modbus-tcp-read-timeout/42576/8 "2021-01-25T16:43:26Z")
Your timeouts appear to be legit… you have the default driver timeout of 2 seconds set and according to Wireshark all the responses are coming back in a little over 2 seconds. ---
**Author:** ![kumar.chellappan](https://avatars.discourse-cdn.com/v4/letter/k/2acd7d/32.png) [@kumar.chellappan](https://forum.inductiveautomation.com/u/kumar.chellappan)\ **Post date:** [January 25, 2021, 5:04pm UTC](https://forum.inductiveautomation.com/t/modbus-tcp-read-timeout/42576/9 "2021-01-25T17:04:05Z")
Oh Gotcha. So I made my Timeout to be 10 seconds but I see the read timeout on the logs. It is also coming up with the clock drift with more than 10 seconds. Changed the timeout to 60s and I don’t get the read timeout in the logs anymore. Thank you very much.