# Very Concerning Read/Write Issues. Important information for all users

**URL:** <https://forum.inductiveautomation.com/t/very-concerning-read-write-issues-important-information-for-all-users/18583>\
**Category:** Ignition\
**Created:** [June 22, 2018, 5:34pm UTC](https://forum.inductiveautomation.com/t/very-concerning-read-write-issues-important-information-for-all-users/18583 "2018-06-22T17:34:33Z")\
**Posts on this page:** 1\
**Showing post:** 7

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**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [June 22, 2018, 9:16pm UTC](https://forum.inductiveautomation.com/t/very-concerning-read-write-issues-important-information-for-all-users/18583/7 "2018-06-22T21:16:15Z")

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> [@thomasdouglasshank](#):
>
> FactoryTalk and PanelViews for these lines and we never had a problem with them

I can assure you that a PanelView, configured with standard tag access, that loses its network connection or suffers a power problem while a momentary button is pressed, will absolutely leave the target bit in the pressed state. This is also true for every single touchscreen product on the market that uses Allen-Bradley's tag data access protocols. And true for any other request/response protocol (Modbus, GE SRTP, Siemens pg). [This topic](http://forum.inductiveautomation.com/t/momentary-pushbutton-latching-on/5373) has a pretty extensive discussion of the issue.

The bottom line is that momentary buttons that cannot be allowed to suffer this kind of failure must use an I/O protocol or have some heartbeat from client all the way to the PLC. I/O protocols repeat the bit status on a schedule, and the PLC itself notices when the schedule is broken. Modern Panelviews offer DeviceNet and ControlNet with scheduled I/O, and Classic Panelviews also offer AB RIO and scheduled Ethernet/IP. Other brands (like Siemens and C-More) also offer scheduled Ethernet/IP (aka Class 1 connections).

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