Applies To:
  • CitectSCADA 1.00, 1.01, 1.10, 1.11, 1.20, 2.00, 2.01

Question: I am getting the runtime error 'Data Size too big 292' on the I/O Server. What causes this error? 

This error is generated when the data being returned from the I/O Server is too large for its buffers. This may occur if you have specified the wrong bitWidth in the function PointNew(), or there is some problem with the protocol driver. The size of the buffer is calculated by the expression 'unitCount x bitWidth / 8'. If the size is greater than 256, this error is generated. The bitWidth is used by only some protocol drivers, so if it is incorrect, the driver will not generate the error. Only the I/O Server will generate an error if the total size is greater than 256.

This error is logged to the SYSLOG.DAT along with the protocol address that caused the error. Look in the SYSLOG.DAT file to find the particular address that is causing the problem. For example:

READ 0000 port1 U150 A1299 73
Thu Feb 24 14:41:20 1994 File (srcw_drv.c) Line (161) Error Data Size to big 292

This error shows that a read request on unit U150, address A1299 with a length of 73 caused the problem. Find this address in your project to fix the problem.

If you are not using PointNew(), or cannot find the bad address, the problem could be in the protocol driver. In this case contact Citect Support for more help.