Question: How do I read the EtherStax ES2161 32bit Floating Point Scaling Registers into my ABB PM571 PLC (version 1.2). The ABB Software I’m using is IN CoDeSys Version 188.8.131.52 and PS501 V 1.3.1. The ES2161 is on the 0-20mA range and inputs are scaled for 0 to 25. I’d like to read back an entire array of real (float) numbers from the modbus addresses in the EtherStax. I do have good communication and can see some data coming back.
Answer: You might have either a “byte order” issue or an offset address issue with the PLC. Try checking out the following: 1. Thru the ES2161 web configuration page, set up the byte order to B1,B0,B3,B2 2. When setting up your array in the PLC, be sure to subtract 1 (ie; offset -1) from the register you’re looking for as published in the EtherStax Manual. Thus, if you want register 3090 (ie; ES2161 register location 43090) then use 3089 location in your PLC.