scada - Force writing only-read register #Modbus -

i wondering, there anyway force writing on 'read-only' modbus register? defining register 'read-only' secure enough or can bypassed??

thanks answers!

the correct way define "read-only" analog variable in modbus map input register. there no function code defined in modbus write input register.

for historical reasons, several vendors maps variables holding registers, theoretically read/write, i.e, there's write multiple registers function. whenever map read variable holding register, must assert write functions fail. however, there's no standard exception code this, holding register should read/write. 1 of modbus' idiosyncrasies.

getting question, if map variable input register, can sure protocol not allow master write it. if, interoperability issues map holding register, protocol allow master use write funcion change value, , block in device implementation.