Port_id with RS232 ?

[brigadier 0]

I use rslinx, and SLC500. My connection use DF1 RS-232. For define the DTL_C_DEFINE parameters, i don't know the port_id. Now i use this definition: "$F8:0,1,float,modify,1kt:0,1,slc500,0" but when i read (with DTL_READ_W), the application crash without error code. I think the error came from parameter port_id-> 1KT:0 this parameter is use for network DH+ but no for DF1 RS-232 Who tried with RS-232 network ??? what the paramater port_id for DF1 Thanks in advance.