Reading T3-22AI input via modbus


Since I have connected up to 4 T3-22AI on the Main RS485 interface of T3-BB, I tried to use the following command to read inputs above the maximum 64 inputs but it doesn’t work.

10 VAR92 = 14.100.MB_REG101

Where 14 is the panel number, 100 the T3-22AI modbus Id and 101 the input 1 of the expansion module.
However with Modbus viewer tool the values of inputs are correctly displayed.

Thank you for your assistance.

I believe we have increased this to 128 with the latest firmware. Update the T3-BB and may as well update the 22i while you are at it.

When the expansion units are set up as expansion IO there is no need for this intermediate step to assign the input to a var, you can use inputs directly in your programs like so:

10 VAR92 = AVG( IN78 , IN80 , IN81 )

Here’s where you configure the expansion modules.

When the inputs are recognized they should show up here, not as virtual but as regular ‘Analog’ inputs, we should change that to ‘UI’ since it could be binary as well depending on the range setting.

T3000 software and devices are now up to date.
In my configuration we have 3 T3-22i

Unfortunately I can see only 64 inputs and not 128 to configure in the T3000 software.

good screen shots, thank you. Chelsea will check into this first thing next work day.

Please update rev65.3, previous firmware versions did not support 1.2.MB_REG for accessing points that had been identified as extended IO, and we fixed this bug in rev65.3.
In general, access to extended IO is similar to access to internal IO, but if the number of extended IO is too large (input more than 64), you may need to use a method such as 1.2.MB_REG.

I’ve noticed that your input table doesn’t seem to refresh all the points. These extension points will refresh quickly if communication is normal.

However I urge you to get familiar with the intrinsic method, IN78, IN99 and so on. It is far easier than looking up registers and massaging data formats. If you are not clear what I mean feel free to ask.