Hach-Lange SC 100 - Manual (Page 37)

Operation
System Setup Menu
33
RELAY SETUP
Select Relay A, B, or C
SELECT SOURCE
Select from none, a connected sensor, or the real time clock (RTC)
SET PARAMETER
Press ENTER to select from the displayed parameters.
SET FUNCTION
Source set to sensor
Alarm: Operates relays in response to the measured parameter. Contains separate High and Low Alarm points, deadbands,
and ON/OFF delay.
Feeder Control: Operates in response to the measured parameter. Can be set for phasing, setpoint, deadband, overfeed
timer, and ON/OFF delay.
Event Control: Controls a cleaning system (or equivalent) on a timed basis.
Warning: Activated when the analyzer detects a sensor warning.
PWM Control: Allows the relay to provide a duty cycled output.
Freq Control: Allows the relay to cycle at a frequency between the minimum pulse per minute and maximum pulse per minute.
Source set to RTC
Timer:
Sets the timer for a cleaning system (or equivalent). Controls the output hold, interval, duration, and off delay.
SET TRANSFER
Sets the relay to Energize or De-energize (user-selectable). Normally, each control or alarm relay is active, responding to the
measured value of its assigned parameter. During calibration, however, the relay can be transferred to a preset on/off state to
suit the application requirements. Select Energize or De-energize and press
ENTER.
FAILSAFE
Allows the user to create a state where the normal condition is energized. The relay is de-energized when an error condition is
experienced. Select YES (Energized) or NO (De-energized) and press
ENTER. YES sets the relay normal condition to
energized resulting in the relay becoming de-energized when an error condition is experienced.
ACTIVATION
Function set to ALARM
LOW ALARM—Sets the value where the relay will turn on in response to decreasing measured value. For example, if the low
alarm is set for 1,0 and the measured value drops to 0,9, the relay will be activated.
HIGH ALARM—Sets the value where the relay will turn on in response to increasing measured value. For example, if the
high alarm is set for 1,0 and the measured value increases to 1,1 the relay will be activated.
LOW DEADBAND—Sets the range where the relay remains on after the measured value increases above the low alarm
value. Default is 5 % of the range. For example, if the low alarm is set for 1,0 and the low deadband is set for 0,5, then the
relay remains on between 1,0 and 1,5.
HIGH DEADBAND—Sets the range where the relay remains on after the measured value decreases below the high alarm
value. Default is 5 % of the range. For example, if the high alarm is set for 4,0 and the high deadband is set for 0,5, then the
relay remains on between 3,5 and 4,0.
OFF DELAY—Sets a time (0–300 seconds) to delay the relay from normally turning off.
ON DELAY—Sets a time (0–300 seconds) to delay the relay from normally turning on.
LOW ALARM—Sets the value where the relay will turn on in response to decreasing measured value. For example, if the low
alarm is set for 1,0 and the measured value drops to 0,9, the relay will be activated.
4.9 System Setup Menu (continued)