Figure 11 shows the Channel model for analog Input according to RIOforPA to illustrate the relationship between the different aspects. The Process Values and their qualifiers are transmitted consecutively and are available for the user program in the Input section of the Process Image.
The PnIoSignalType Objects “01_AI_1_Value” and “03_AI_2_Value” representing the Process Values in the PnIoTelegramType Object “Input” connect to the “ProcessValue” Variables which are components of the Input Channels “AI_1” and “AI_2” using a 0:RepresentsSameEntityAs Reference.
The PnIoSignalType Objects “02_AI_1_Q” and “04_AI_2_Q” representing the Process Value Qualifiers transmitted alongside the Process Values they belong to connect to the “QualifierValue” Variables also using a 0:RepresentsSameEntityAs Reference.
The direct connection of Signal Objects representing status data and qualifier Variables using 0:RepresentsSameEntityAs References in the way shown in Figure 12 is only possible for analog Input and analog Output according to RIOforPA, since only analog RIOforPA transmits the status data (= qualifiers) alongside to each Process Value as separate Signal in the Telegram.
Digital RIOforPA Input and Output Channels transmit value and status packed into one byte (see [RIO PA] sec. 184.108.40.206 “Discrete Values”). Figure 13 shows the digital Output Channel model according to RIOforPA.