In. w.c.), Pressure, Control mode – Dwyer DHII User Manual

Page 7

SETTING SET POINTS AND ALARMS

The hot key provides direct access to the Set Point and Alarm MENU. The Set Point and Alarm
MENUS that are displayed are based upon the Control (CtrL) SUB MENU.

SP/AL

Visible when

mode =

CONTROL MODE

SET POINT ADJUSTMENT

Adjusting the Digihelic

II Controller Set Points is quick and simple. Instead of setting a set point and

deadband, simply adjust SP1H or SP2H for the desired relay turn on point, and then adjust SP1L or SP2L
for the desired relay turn off point.

PRESSURE

TIME

0.2

0.4

0.6

0.8

1.0

(in. w.c.)

In the above graph, an instrument with a 1.0˝ range would have the SP1 relay turn on at 0.8˝ and off
at 0.4˝. SP1H sets the relay turn on point, and SP1L sets the relay turn off point. The relays outputs
normally function in the direct acting mode, which means the relays turn on with an increase in
pressure. SP1 may be configured to act as a reverse acting relay (refer to the 1SP SUB MENU setting,
page 15). When set for reverse acting, SP1H sets the relay turn OFF point, and SP1Lsets the relay turn
ON point. SP2 is always direct acting.

SP/AL