The attached files are to make it easier to use the Modbus driver in InteractX and Interact Xpress with the P Drive Index steps.
Since the Modbus protocol handles all memory requests as a full 16 bit word and some addresses in the P Drive are only a Byte in length, it is necessary to force the Modbus driver to not ask for data in blocks of registers.
If the settings do not prevent reading blocks of memory, your data returned will be wrong as it skews the data whenever it runs into a Byte data type from the P Drive. The symptom will be that when you write to the tag, the value received by the drive is correct (writes are single register) but the data read back and displayed is wrong.
Set the Modbus driver as follows for "Settings" and "Block Sizes" leaving the other settings set to their default values.
The zip file download below includes a Interact Xpress application with a single panel that connects to Indexes 0 - 3 as an example and test to make sure you can connect to the RS422 port on the P Drive. Also in the zip are an Excel Workbook with tags formatted for copy and paste import into InteractX and a sheet that was used to create the Text file Tag Import file for Xpress.
The worksheet includes addressing for the entire set of indexes in the P Drive.
The Xpress application is a 3.1 project .lrp file that you can copy into your Xpress Local Files path. If you are not sure where that may be, look in the Xpress Home screen at the top left.
DM 05/06/2019