User manual

76 Publication LOGIX-AP010B-EN-P - May 2010
Chapter 3 Software Conversions Instructions
Overflow Jump Function JO
With S5 you can work with decimal number in the range -32768 to +32768. If the result of the arithmetic operation is
outside this range then S5 sets the overflow bit, OV. The instructions JO can be used to program a jump if this bit is set.
This is often used in programs to run error handling code when values exceed their expected range.
With RSLogix 5000 software, the data type DINT can be used to store a 32-bit signed integer value between the range
-2,147,483,648 to +2,147,483,647 therefore overflow of data is not usually an issue. However, if required, a combination of
a greater than (GT) or less than (LT) comparison instruction and a jump (JMP) instruction can be used in RSLogix to exceed
a jump if values exceed a specified range. RSLogix 5000 software also includes an arithmetic overflow status flag (S:V) that
is set if a value cannot fit into the destination because the value is greater than the maximum value for the destination or
less than the minimum value for the destination. This overflow bit can be used in conjunction with the JUMP (JMP)
instruction to replicate the functionality of the S5 JO instruction.