Applies To:
  • CitectSCADA 1.20 2.00 2.01 3.00

Question: The documentation of the ComRead() function says that is will only accept up to 128 characters. Is this likely to cause loss of data when the baud rate is high? 

The 128 characters limit on the ComRead() is only there as a cicode string is limited to this size. There are extra buffers in the serial driver which will stop any data from being lost. These buffers are 1600 bytes in length and should be able to handle very high data rates. See KB article Q1043 for this information.

I feel that the com port functions in cicode should be able to keep up with the data transfer with fast baud rates. I have only ever heard of users having problems with loss of data when they where reading 1 character at a time. You should make sure that your cicode is designed to read the com ports in big blocks (128 characters) to get the best performance. If you read data in big blocks the ComRead function will have no problem keeping up with baud rates of 9,600 to 19,200 baud.