
Lake Shore Model 340 Temperature Controller User’s Manual
7-6
Analog, Digital, Alarm & Relay Operation
7.3.6 Input
Alarm
Reset
The
Alarm Reset
key performs the immediate action of resetting all latched alarms. If any alarm is latched
active and the alarm condition has been corrected, pressing the
Alarm Reset
key deactivates the alarm. If
the alarm condition is not corrected, the alarm is not deactivated. Non-latching alarms deactivate when the
alarm condition is corrected without the Alarm Reset function.
7.3.7 Audible
Beeper
The audible alarm beeper can be turned on or off for the entire instrument. To turn on or off the audible alarm
beeper, press the
Options
key and then press the
More
key and the
RELAYS & BEEPER SETUP
screen
appears. Press the
Next Setting
key until the beeper field highlights. Use the
s
or
t
key to turn the beeper
on or off and press the
Save Screen
key to store the change. The default setting is On.
7.4 HIGH AND LOW RELAYS
The Model 340 has one high and one low
relay. See Figure 3-7. They are most
commonly associated with the alarm feature
discussed in Paragraph 7.3. The relays can
also be put in manual mode and controlled
directly by the user from the front panel or over computer interface. Relay parameters are shown on the
Relays and Beeper Setup
screen, which is accessed by pressing the
Options
key, then pressing the
More
key. The relay and beeper
Status
shown on the right side of the screen is for monitoring only and cannot be
changed by the user.
7.4.1 Selecting a Relay Mode
To select a relay mode, press the
Options
key and then press the
More
key and the
RELAYS & BEEPER
SETUP
screen appears. Press the
Next Setting
key until the appropriate relay mode field is highlighted. Use
the
s
or
t
key to select a mode for that relay. Use the
Next Setting
or
Enter
key to make more changes or
press the
Save Screen
key to store the changes. The default setting is Off.
7.4.2 Manually Setting a Relay
To manually control a relay it must be in the manual mode, as described in Paragraph 7.4.1. A relay setting of
“Off” puts the relay in its normal state, while “On” puts the relay in the opposite state.
To change a relay setting, press the
Options
key and then press the
More
key and the
RELAYS & BEEPER
SETUP
screen appears. Press the
Next Setting
key until the appropriate relay setting field is highlighted. Use
the
s
or
t
key to select on or off for that relay. Use the
Next Setting
or
Enter
key to make more changes or
press the
Save Screen
key to store the changes. The default setting is Off.
OFF
Relay is set to Off
MANUAL
Relay manual control (Paragraph 7.4.2)
ALARMS
Relay triggered by alarm (Paragraph 7.3.5)