Issue
What Modbus Function Codes are supported on the Magelis that are using Vijeo Designer Runtime?

Product Line
Vijeo Designer Runtime
Harmony HMIGTO/GTU/STO/STU, Magelis XBTG/GH/GK/GT, Magelis iPC, Panel PC, Box PC

Environment
Physical HMI

Resolution
Below is the Table of Modbus function codes used by the Magelis/Harmony HMI families running Vijeo Designer.

Classes	Function name	Function code (hex)
Basic	Read Holding registers	03
Base	Write Multiple registers	10
Regular	Read Coils	01
Regular	Read Discrete Inputs	02
Regular	Write Multiple Coils	0F
Regular	Diagnostic	08
Supplementary services	Read Input registers	04
Supplementary services	Write Single Coil	05
Supplementary services	Write Single register	06
Supplementary services	Read Device Identification (only for Modbus TC/IP with target machine server)	2B

By default the HMI uses the Function Code 10 (FC 10) to write multiple registers.
However, some devices do not know this function code. When a device doesn’t know FC 10, the HMI will automatically use (without any error code) FC 06.
In the same way, the HMI will use FC 05 instead of FC 0F. In addition, FC 06 and FC 05 will always be used if Preferred Frame Length is set to Minimum possible.

Released for:Schneider Electric Ireland