Rounding errors in Quick Client

When using the OPC Quick Client to write a float value 39153.58 it only returns one decimal place, 39153.6. Other values such as 1.24, 39.75, and 102.93 return the correct value with two decimal places. Why does it round to one decimal at this value?

There is a limitation in Quick Client that will display only 6 significant digits on a float value. Therefore, there will be issues with any float value (with or without decimal places) greater than 6 digits.

For example, 4,000,000 will be converted to scientific notation, 4e+006, 350.9756 will round to 350.976 and 39513.58 will round to 39513.6.

This is only a limitation of the OPC Quick Client and if your client program will support more digits, TOP Server will not round these values— so 39513.58 will be returned to your client program correctly.