Timed Versus Normal (Non Timed) Control; Validation Error And Autofix - Set Point Control Only - YSI MultiDO 5400 User Manual

Set Point Alarm Values
Alarm values set the acceptable control range. Alarm system(s) do not become
active when values are within acceptable control range. See figure 4.8 - page 155.
Enable and configure system alarm(s) to activate alarm output devices(s), view
alarm icons, hear audible alarm and/or receive alarm notifications sent via email or
cell phone (SMS) - page 90. Configure high and low alarm values to set alarm
thresholds. Alarm system(s) becomes active when value is ≤ low alarm value or ≥
high alarm value. Enabled alarm relays energize if alarm condition exists for the
general alarm hold off time. Alarm relays are energized until one of the four soft-
keys
one of four softkeys resets the alarm system. Alarm systems become active again
if, after the alarm hold off period, the alarm condition still exists. Alarm hold off is
configured in the General Alarm menu.
When the General Alarm is enabled, (with or without enabled relay), the general
alarm system becomes active when any system alarm is active. See General Alarm
- page 131.
System low alarm range starts at -1 significant digit below low control value. High
alarm range starts at +1 significant digit above high control value.
Notes:
- Configure sensor alarm relays using AquaManager - see page 150.
-
It is important to keep the 5X00 at the Run Screen during normal opera-
tion. Alarm functionality (email alarms, activation of enabled alarm relays,
alarm icons, and buzzer) is suspended when 5X00 is not at Run Screen.
- Alarm icon(s) display at the Run Screen when alarm condition(s) exists for
longer than the general alarm hold off time. See Icons - page 76.
- Press at Run Screen to display active sensor and aux system relays.
- to display events created by control and alarm relays - see Event Log
- page 120.
- Alarm relays are not energized if the 5X00 DO sensor value reads "Over" or
"Under. "
- "Over" and "Under" are not displayed for aux temperature systems when
temperature values are outside the temperature range specification - see tem-
perature range specification - page 15. Temperature system alarms will not
operate correctly when values are outside the temperature range specification.
- See Wire Relays - page 54 for information on wiring control output devices
on a 5X00 instrument. See IOEM/REM Safety and Installation guide>Chapter
3>Step 4>Wire REM Relay Outputs.
Configuring the 5X00
is pressed regardless of sensor value. Pressing
YSI 5X00
156

Timed versus Normal (non timed) Control

Timed control is available for high temperature and high and low analog aux and
E-Aux systems. In timed set point control mode control relays are controlled by tim-
ers as opposed to water system value. All systems can be controlled in a non timed
(normal) control mode by configuring dose on/chiller on time to 0. This will cause
the system's control relays to remain energized until the set point value is reached.
In a set point timed mode, a control relay energizes for the dose on time regardless
if the sensor reports that a value has returned to the set point value. The control
relay deenergizes at the end of the dose time and then waits a user configured "wait",
"dwell", or "hold off " time before resampling. If, after the wait time, the system is still
in control range the control relay will energize again for the dose on time.
In the case of a temperature high set point time control mode it is recommended
to configure the chiller hold off time to a value of eight (8) minutes, or more. This
amount of time will help to avoid chiller compressor damage due to many on/offs.
Notes:
- A chiller off time must be configured in the timed mode or the control relay
will never de-energize.
- Since most heaters and chillers have their own thermostats, their thermostats
can be used as a backup temperature control system. Set the heater thermostat
control several degrees above the desired temperature and the chiller thermo-
stat control several degrees below the desired temperature.
- Active sensor control timers are reset after systemwide events. Systemwide
events de-energize relays. Example - chiller on time is configured for an eight
(8) minute on time. Energized chiller (control down) relay de-energizes when
5X00 goes into Svr Hold. The chiller on relay had been energized for three (3)
minutes before the Svr Hold occurred. The Svr Hold time is one (1) minute. If
the sensor is reporting control low condition after the service hold time period,
the chiller on time will be for eight (8) minutes and not the remaining five (5)
minutes of the chiller on time prior to entering Svr Hold.
- Control down relay (chiller) energizes for original "on time" if chiller "on
time" is reconfigured when relay is energized.

Validation Error and Autofix - Set Point Control Only

When an invalid value is entered at the numeric keypad a Validation Error window
displays. An invalid value is either a value outside the range of the sensor system or
a value that breaches other settings within the sensor system. Autofix occurs when
a high or low control value is entered that breaches the set point value. Examples
are provided below:
Configuring the 5X00
YSI 5X00
157