Relays - Lakeshore 335 User Manual

76 c 5: Advanced Operation
HAPTER

5.7.2 Relays

Model 335 Temperature Controller
There are two relays on the Model 335 numbered 1 and 2. They are most commonly
thought of as alarm relays, but they may be manually controlled also. Relay assign-
ments are configurable as shown in FIGURE 5-7. Two relays can be used with one sen-
sor input for independent high and low operation, or each can be assigned to a
different input.
Relay 1
Off On A Alarm
Manual off Manual on Follows
relay remains in relay remains in
Input A
normal state active state
Both
Alarms
Off Manual off—relay remains in the normal state
On Manual on—relay remains in the active state
A Alarm Relay will follow Input A alarms
Both Alarms Relay active when either the High or Low Alarm is active
Low Alarms Relay active only when the Low Alarm is active
High Alarms Relay active only when the High Alarm is active
B Alarm Relay will follow Input B alarms
Both Alarms Relay active when either the High or Low Alarm is active
Low Alarms Relay active only when the Low Alarm is active
High Alarms Relay active only when the High Alarm is active
When using relays with alarm operation, set up alarms first. The relays are rated for
30 VDC and 3 A. Their terminals are in the detachable terminal block on the
Model 335 rear panel.
In the Off mode the relay is un-energized, leaving the normally open (NO) contacts
open and the normally closed (NC) contacts closed. In the On mode the relay is ener-
gized, so the NO contacts will be closed and the NC contacts will be open. In the Alarm
mode the relay will activate based on the state of the configured Alarm Input sensor.
When the Alarm to Follow parameter is set to Low, the relay will energize if the con-
figured Alarm Input sensor goes into a low alarm state. If it is set to High, the relay will
energize if the configured Alarm Input sensor goes into a high alarm state. If the
Alarm to Follow parameter is set to Both, the relay will energize if the configured
Alarm Input sensor goes into either a low alarm or a high alarm state.
Menu Navigation:
RelaysQ(Relay 1, Relay 2)QMode (Off, On, Alarm)
RelaysQ(Relay 1, Relay 2)QMode (Alarm)QAlarm Input (Input (A, B))Q
Alarm to Follow (Low, High, Both)
Default:
ModeQOff
Alarm InputQInput A
Alarm to FollowQBoth
Interface Command: RELAY
B Alarm Off
Follows Manual off Manual on
relay remains in relay remains in
Input B
normal state active state
Low High
Alarm Alarm
FIGURE 5-7 Relay settings
Relay 2
On A Alarm B Alarm
Follows Follows
Input A Input B
Both Low High
Alarms Alarm Alarm