Automation Direct GS4 VFD Modbus TCP

Ignition
1

Didn't seem to have luck with this direct device when searching on the forums so forgive me if there is a post already.

I'm having trouble getting valid Modbus TCP data from an Automation Direct GS4 VFD.

I am able to use software such as ModPoll to read all values via Modbus TCP, however, Ignition Quick Client reads 'null' and tag browser in designer shows 'Bad' for every address outside of the first 19 (40001 - 40019 are the first block before a gap).

Ignition is able to read data from 40001 - 40019, however, it's nonsense that does not match ModPoll or the physical device.
For Example: ModPoll reading the Base Frequency at address 40003 returns 6000 (60 Hz), where Ignition OPC Quick Client returns 1553.

I have the Zero-Based setting matching ModPoll and have tried Span Gaps On and Off with no effect.

I'm really not sure what could cause this issue. We have confirmed all settings in the device are correct or else I wouldn't get correct data via ModPoll.

I've tried reducing the number for Max Holding Registers Per Request from the default 125 down to 75 and even 50, which are completely arbitrary numbers, with no effect and am now at a loss for what I can even try?

One more bit of information that might be useful for clarity: ModPoll is being ran via the same switch that the Ignition Gateway is running on so I'm not concerned with port configuration or other network settings.

2

Are you specifying a slave unit number? Ignition defaults to unit zero for best results with Modbus TCP, but devices that are really RTU typically need unit one (anything but zero, really).

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3

How have you defined the address(es) in Ignition? Have you tried making a tag with just a path of [device]1.HR3? Show an example tag configuration if you can.

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4

Oh dear, I had to dig for the ModPoll screenshots from the pro that was on site last week and it shows a Slave ID of 1. . .

I modified one of my tag addresses to include the ID: [device]1.HRxx and it is now reading correctly.

Thank you both for your quick responses and I'm happy/embarrassed at the ease of the result :grinning_face_with_smiling_eyes:

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