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Decimal placement for numeric values, Decimal placement for percentage values – Watlow CPC400 User Manual

Page 94

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Chapter 3: Operation and Setup

CPC400 Series User’s Guide

80

Watlow Anafaze

Doc. 0600-2900-2000

Decimal Placement for Numeric Values

Numeric values that are in the loop’s engineering units are
stored as integers. The number of decimal places that are
assumed when a parameter value is stored in the controller
depends upon the Input type and Disp format parameter
values for the loop. See Table 3.16.

Table 3.16

Number of Decimal Places for Nu-
meric Values via Modbus or Logic

To determine the integer value to set in the controller,
move the decimal to the right the number of places speci-
fied.

For example:

If a loop has a process input with a display format of
-99.99 to 300.00, values are stored with two decimal
places. If you read a value in the set point register of
2500, you should interpret that value as 25.00.

If a loop has a thermocouple input and you want to set
the Alarm High SP parameter to 355 through Modbus
or logic, you should set a value of 3550.

Decimal Placement for Percentage Values

Percentage values are stored internally in tenths of a per-
cent, such that 1000 corresponds to 100.0 percent. Divide
values by ten when reading, and multiply values by ten be-
fore writing.

Input Type

Display Format

Decimal

Places

Any thermocouple or
RTD

-999 to 3000

1

Process or pulse or
soft integer used as
an Analog Input

-999 to 3000

1

-9999 to 30000

0

-999.9 to 3000.0

1

-99.99 to 300.00

2

-9.999 to 30.000

3

-0.9999 to 3.0000

4