# Siemens S7-300 Driver - Losing power to one device kills comms to all devices

**URL:** <https://forum.inductiveautomation.com/t/siemens-s7-300-driver-losing-power-to-one-device-kills-comms-to-all-devices/27069>\
**Category:** Ignition\
**Tags:** ignition80\
**Created:** [August 1, 2019, 5:38am UTC](https://forum.inductiveautomation.com/t/siemens-s7-300-driver-losing-power-to-one-device-kills-comms-to-all-devices/27069 "2019-08-01T05:38:24Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![gavin.strack](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/gavin.strack/32/10064_2.png) [@gavin.strack](https://forum.inductiveautomation.com/u/gavin.strack)\
**Post date:** [August 1, 2019, 5:38am UTC](https://forum.inductiveautomation.com/t/siemens-s7-300-driver-losing-power-to-one-device-kills-comms-to-all-devices/27069/1 "2019-08-01T05:38:24Z")

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I’m new to Ignition and currently building to new system talking to a number of Siemens S7-300 PLCs and RIOs. I have about a dozen device connections set up currently and working well, with a number of tags of various data types being polled and historised using a MS SQL Server database connection.

I have 3 Gantry PLCs and have had working connections for several days. Today however, I noticed the device connection status for Crane 1 and 2 were both constantly disconnected/connecting. I also noticed that all configured tags in the Tag Browser in the designer all had red exclamation symbols (i.e. no good data). - not just for the tags for these 2 connections, but for ALL devices.

I disabled both of these connections and all the data for all the other devices cleared and started showing good data again.

I’m struggling to understand why the loss of 2 device connections would impact all device connections. Is this something peculiar to the S7-300 driver? Is it an OPC UA issue? Have I configured something wrong? I haven’t seen this before so any assistance or advice would be appreciated.

Thanks!

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**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:** [August 1, 2019, 12:12pm UTC](https://forum.inductiveautomation.com/t/siemens-s7-300-driver-losing-power-to-one-device-kills-comms-to-all-devices/27069/2 "2019-08-01T12:12:31Z")

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The drivers/server are not written in a way that would explain this. My first instinct would be looking at your network or something, not at Ignition.

If you can reliably reproduce this situation a call to support might help narrow it down, though.