You get the current status by READ. The current status changed since the last access isreturned by READDELTA. The bytes have the following structure:Bit No. 7 6 5 4 3 2 1 0Read x x RTS DTR CD RI DSR CTSReadDelta x x x x CD RI DSR CTSValue Description0000h no error8x24h Error SFC parameter x, with x:n 1: Error at WRITEn 2: Error at MASKWRITEn 3: Error at READn 4: Error at READDELTA809Ah Interface missing809Bh Interface not configured (SFC 216)10.1.2 FC/SFC 216 - SER_CFG - Parametrization PtPPlease note that this block can only be used in CPUs from VIPA or inS7-300 CPUs from Siemens!You may de-activate the DP master integrated in the SPEED7-CPU via a hardware con-figuration using object properties and the parameter "Function RS485". Thus release theRS485 interface for PtP (point-to-point) communication. The RS485 interface supports inPtP operation the serial process connection to different source res. destination systems.The parametrization happens during runtime deploying the FC/SFC 216 (SER_CFG). Forthis you have to store the parameters in a DB for all protocols except ASCII.n Data, which are written into the according data channel by the PLC, is stored in aFIFO send buffer (first in first out) with a size of 2x1024byte and then put out via theinterface.n When the interface receives data, this is stored in a FIFO receive buffer with a size of2x1024byte and can there be read by the PLC.n If the data is transferred via a protocol, the adoption of the data to the according pro-tocol happens automatically. In opposite to ASCII and STX/ETX, the protocols 3964R,USS and Modbus require the acknowledgement of the partner.n An additional call of the FC/SFC 217 SER_SND causes a return value in RETVALthat includes among others recent information about the acknowledgement of thepartner. Further on for USS and Modbus after a SER_SND the acknowledgementtelegram must be evaluated by call of the FC/SFC 218 SER_RCV.READRETVAL (Return value)DescriptionCommunicationVIPA SPEED7Serial CommunicationSerial communication > FC/SFC 216 - SER_CFG - Parametrization PtPHB00 | OPL_SP7 | Operation list | en | 18-30204
