Straton IEC60870-5-104 Receiver Set poit command

[Davrigo]

Good morning, I should configure a slave 104 to receive set point command, but I have a

a question to ask you. I receive the normalized value correctly, but I would like to know if there is a bit that gives me the information of "setpoint commad received" ... Thanks

[ursulak]

in iEC60870 protocol the commands are 'write-only'. Thus, a master can send new value (e.g. of a T48 Information Object - a variable) but when such variable changes value in slave - there will be no frame sent to the master.

In practice this means that you do not need any additional bits to detect new incoming command. As for normalized value the legal range is only -1.0 to 0.9999, you can define that after the execution of a set-point command the T48 variable gets value ("idle") e.g. -2.0; so a value a master cannot send. Then a new command, even when with the same value as command before, will change the value of your T48 variable. 

[Davrigo]

Thank you so much..