Programming
Chapter 3
310
Error Message
If the resultant sum has more than six integers, the error bit (bit 14) is set
indicating overflow.
AF1 Subtraction Function
An AF1 subtraction function operates on two 6-digit BCD numbers and
presents the result in a third 6-digit BCD number.
(+
XXX XXX.) - (+XXX XXX.) = +XXX XXX.
How to Enter an AF1 Subtraction Function
To program an AF1 subtraction function, perform the following steps:
1. Press [SHIFT] [EAF] or [SHIFT] [SCT] on the keyboard of your
industrial terminal. Figure 3.1 appears on the CRT.
2. Enter 02, the function number for AF1 subtraction.
This entry identifies that the function entered is to perform an AF1 subtraction
and that the processor use the data table format shown in Figure 3.6 when
executed. Operands 1 and 2 represent the two 6-digit numbers whose difference
you want to find. The six digits of operand 1 are represented in BCD by the
group of bits labeled digit 1 through 6. Digit 1 and digit 6 are respectively.
This digit labeling system also applies to operand 2 and the result.
