YSI IQ SensorNet DIQ/CR3 - Manual (Page 18)

Settings MIQ/CR3; DIQ/CR3
4 - 4 ba76032e01 01/2012
Monitoring limiting
values using one or two
relays
Fig. 4-1 Switching points for relays with the function of a limit indicator
A switching delay (t) can be set up for each relay for switching
processes. This is the time period for which a limiting value must be
exceeded before the relay switches. This prevents frequent switching if
the measured values are close to the limiting value.
1 Upper limit value (relay 1) exceeded
2 Selected switching delay t1 for relay 1 expired
Relay 1 switches
3 Hysteresis for upper limiting value (relay 1) undercut
4 Selected switching delay t1 for relay 1 expired
Relay 1 switches back
5 Lower limit value (relay 2) undercut
Selected switching delay t2 for relay 2 expired
Relay 2 switches
6 Hysteresis for lower limiting value (relay 2) exceeded
Selected switching delay t2 for relay 2 expired
Relay 2 switches back
Time
Measured
value
UL
LL
Hysteresis UL
Hysteresis LL
3
5
Relay 1
Relay 2
4 1
2
t1
t1
6
t2 t2