Float value coming from modbus simulator shows its increased by 1 only in case of even numbers

i have ignition 8 downloaded and i also have a modsim simulator running and configured to read float.
i am able to read the values, but there is small increment to the value that i have entered in simulator. If i enter 331 in simulator, i can read it correctly in ignition. But if i enter an even number for ex: 332, i dont see that value,. instead, i see 333. How can fix this ?