Try requesting all of the registers together. The result is that the device will report an error when you try selectively polling registers. For a controller with 100 registers, a request with offset 96 and length 4 would succeed, a request with offset 96 and length 5 will generate exception 02. More specifically, the combination of reference number and transfer length is invalid.
![modbus poll illegal data address modbus poll illegal data address](https://community-assets.home-assistant.io/original/3X/9/0/9061a95046098c06ab47fcfaffb51c4d2d477737.jpeg)
Instead, they are hardcoded to respond to certain Modbus messages. The data address received in the query is not an allowable address for the server (or slave).
#Modbus poll illegal data address software#
I am working with CCS modbus slave with pic18f46k22 that sends data to modbus poll software but it will send wrong values. Some devices do not fully implement parsing Modbus commands. back to the host if the Data Address is illegal or if the write command. Send them to RTU with pic18f46k22 write error Register Address A data base start location within a Modbus address used to. Polling Data from MODBUS RTU AUG-0080-00 2.
#Modbus poll illegal data address free#
0 is reserved for broadcast messages from the master device 1 - 247 are free to use for each unique device 248 - 255 are reserved To set the ModBus address the dip switches can be set in either the 0 position or the 1 position. Polling PLC data registers implies the following steps : 1. 2 ModBus Con guration Addressing Th e ModBus addressing space is comprised of 256 diff erent addresss. The Modbus data address for the discrete input. Please do not post bug Reports on this forum. The objective of this document is to explain how the Flexy can poll data registers out of one or more PLCs using MODBUS RTU. This application sets up the Modbus to BACnet mapping objects through the use of a PC. CCS :: View topic - modbus RTU with pic18f46k22 write errorįAQ Forum Help Official CCS Support Search Register Profile Log in to check your private messages Log inĬCS does not monitor this forum on a regular basis.