Online Field Total Restrictions; Example - IBM 3742 Reference Manual

Online Field Total Restrictions
To ensure the accuracy of the field total in the accumulator,
remember the following restrictions:
• When using more than one program to process a record,
all programs used must have identical field total fields.
• When deleting a record or backspacing to a previous
record from a partially entered, updated, or verified
record, select the same program for deleting and back-
spacing over the record that was used to create that
record.
• A field programmed to have the contents of an accumu-
lator read into it must be preceded by at least one pro-
grammed manual field and must not be followed within
the same record by a field totals field relating to that
accumulator.
• Backspacing over a previous record with a field pro-
grammed to have an accumulator read into it is not
allowed.
• After updating a record, deleting a record, or correcting
a record in the verify mode, all succeeding fields pro-
grammed to accept an accumulator total that were
affected by the operation must be executed. To execute
this field total operation, record advance to the record
that the accumulator is to be read into, select the
correct program level, and field advance over the field
that is to contain the total.
• In update mode, a field that is to have a total read into
it is not executed if
R
EC ADV is pressed before the
cursor enters that field.
• Selection of second disk functions, communications
functions, and print functions other than print record
should be avoided to maintain online field total integrity.
• Program load functions should be done under program
level 0 to maintain online field totals integrity.
32
Example
The transactions for one day of business are:
Item Number Item Cost
31621 1621
10897-
734
41621 1621
10021 121
21100 1100
Total Cost 5197
Each transaction record contains the item number and item
cost. Each item sold is considered one transaction. After
the transaction records are entered, the operator must
determine if any of the transactions were skipped during
the entering process. To do this the cost field must be pre-
computed, and programmed as
a
field totals field, and the
total cost from the accumulator must be read into a
summary record. Then the field totals total can be com-
pared with the precomputed total cost. If the totals are
equal, all the transactions were entered. If the totals are
not equal, the larger total can be subtracted from the
smaller total to determine which transaction was skipped
or duplicated. For example, if the field totals total is 4463,
subtracting 4463 from 5197 gives 734 which indicates that
the transaction for item number 10897, cost 734, was not
entered on the disk.
To use the cost as a field totals field to be accumulated in
accumulator 2, use the following program:
N ---- R 2 -------- E
To read accumulator 2 into the summary record and reset
the accumulator to zero, use the following program for
the summary record:
N----
B8--------E