Exception Response , Illegal Data Address

[mushfiq-heraclius-xen]

while trying the example "simple" using "Simply Modbus" software as a master and an Arduino UNO as slave, i'm getting "Exception Response" & "Illegal Data Address"

can anybody tell me why this is happening ??

[yaacov]

Hi, thanks for issue, I added a "help wanted" label in case someone can help.
p.s.
It may help to have a dump of the request and response data, it may give a person trying to help more context.