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General software, Figure 8.9 - heater with digital event – Watlow Series 988 User Manual

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WATLOW Series 988 User’s Manual

8.9

General Software Features, Chapter 8

General Software

TL

W

WA

PROCESS

L1

L2

L3

L4

DEV

% OUT

DISPLAY

MODE

AUTO

MAN

SERIES 988

input 1

input 3

(event input 1)

output 1

limit

limit
sensor

heater

temperature
sensor

switch

Sample Application
A manufacturing engineer is building an application that needs to switch
to an idle temperature at the end of a batch and maintain that tempera-
ture until the next batch is loaded, with minimum operator interaction.

By connecting an external switch to the digital event input, he can select
either the operating temperature or the idle temperature with the flip of a
switch. The idle set point prompt is enabled by setting the Event Input 1
prompt

[`Ei1], in the Global Menu, to idle set point [Idsp]. The idle set

point value is accessed by pressing the MODE key µ from anywhere in
the display loop. When the switch closes, the lower display will indicate
the idle set point, and the controller will maintain this new set point.

Figure 8.9 - Heater
with digital event.