1) You will need to use the PORT_CFG block to setup the serial parameters. I suggest that you use 9600 baud, 8 data bits, 1 stop bit and no parity, and no flow control. You will need to set REQ high and wait for DONE to be set true and STATUS = 0. This will indicate that the serial port on the CM 1241 has been configured.
2) Configure hyperterminal to the same serial setup.
3) Connect the PC to the CM 1241 using a suitable cable (transmit and receive lines should be crossed and ground connected to ground).
4) Call up the CM 1214 from within hyperterminal.
5) To receive data on the CM 1214 you will need to use the RCV_PTP block. Configure the block as instructed in the S7-1200 system manual. Connect a suitable storage area to the BUFFER input (this would normally be a shared DB). Set EN_R true. Now any data that is type on the PC keyboard will be placed in the storage area supplied at the BUFFER input.
6) To send data from the CM 1214 you will need to use the SEND_PTP block. Configure the block as instructed in the S7-1200 system manual. Connect a suitable storage area to the BUFFER input (this would normally be a shared DB). Connect a suitable rising edge generator to the REQ input. You could use a JK flip-flop with both the J and K inputs set high running in a cyclc OB to do this. This will generate a rising edge at half the frequency of the cycle time of the OB. The data that is loaded to the storage area DB will then be displayed in the hyperterminal window.
I suggest that you read section 12.3 (Point-to-Point (PtP) communication) of the S7-1200 system manual.
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