Having problem with reading Modbus registers in a Micro 800 PLC

Followed the device setup, connected, created address registers, data is "bad". Although it appears it recognizes the register as valid.

Use "1" not "40001" for the address.

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Following, cause I could never get them to work at my site. lol.

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I have followed the tag setup and still get this. Its odd, I can see the tag values in quick client, and can actually change the PLC tag from the ignition screen I made. But tag is not working correctly acccording to this.

Screenshot 2022-10-12 121019|690x227

Do you have gaps in the Modbus addresses assigned to tags? If so, you will need to turn off the Ignition Driver's "span gaps" setting.

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After going through everything several times I still do not get quality data from source back to Ignition. I can write a value out to the modbus, but it does not read properly. Nothing I change has fixed this.

This is to a Micro850 Allen Bradley PLC.

See quality message in image.

Screenshot 2022-10-13 104718

Show your driver settings for the M850 device. Including the advanced settings.

Have you tried including a node address? Like [M850]1.HR1 ? Ignition's driver uses node zero if not given.

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The strange thing is being able to write and change the variables in the 850. So I know it works one way.

Turn "Span Gaps" OFF, as I recommended above.

Tried earlier with no luck, will try again.

You do not need to define any addresses.

I have started over using a different method which works. But I still think the original method "Should" have worked.

I created Modbus registers in the global tags table of the Micro850. Arrays 1-50 of coils and registers. In the user program I then map needed data from the source to these registers. In Ignition I read these register arrays instead of the source coil/int. Bi directional operation works. So I basically created a buffer for the data in the Micro. Nothing more.

This is what I changed to.

Screenshot 2022-10-13 131300

Note that native access to ML8xx global tags (with some restrictions) is now available. Avoid the labor of setting up modbus on your tags:

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