# Modbus Tags "Bad\_NotConnected" When polling more than one device **URL:** \ **Category:** Ignition\ **Tags:** modbus\ **Created:** [July 7, 2024, 9:20am UTC](https://forum.inductiveautomation.com/t/modbus-tags-bad-notconnected-when-polling-more-than-one-device/92865 "2024-07-07T09:20:03Z")\ **Posts on this page:** 1\ **Showing post:** 3
**Author:** ![Ali\_R](https://avatars.discourse-cdn.com/v4/letter/a/4491bb/32.png) [@Ali\_R](https://forum.inductiveautomation.com/u/Ali_R)\ **Post date:** [July 8, 2024, 5:51am UTC](https://forum.inductiveautomation.com/t/modbus-tags-bad-notconnected-when-polling-more-than-one-device/92865/3 "2024-07-08T05:51:18Z")
The diagnostics Tag shows Good connection without errors. But I have investigated it further and it seems that the poll requests are being sent to all 4 slave devices at once resulting in Frame and CRC errors by slaves. I think I am experiencing the same problem here: > [@Add delay between Polls for devices in Modbus RTU](https://forum.inductiveautomation.com/t/add-delay-between-polls-for-devices-in-modbus-rtu/40591/6): > > Unfortunately I notice today that driver issue all poll request at the same time for all IDs in the bus. So every device try to answer the request base on their ID and we have collisions detection on the RS485 bus. It seems the one who write the driver think it works as TCP connection and doesn’t care about serial limitation. > I hope IA fix this issue unless the driver is totally useless in serial mode. --- _[View the full topic](https://forum.inductiveautomation.com/t/modbus-tags-bad-notconnected-when-polling-more-than-one-device/92865)._