Yokogawa DO402 Dissolved Oxygen Analyzer - Manual (Page 56)

IM 12J05D02-01E
5-20 Parameter setting
5-3-5. Contact outputs
Code 40, *S1 & *S2 Process relays can be set for a variety of alarm and control function.
41, 42 & 43
Digit “X” sets the type of trigger:
Off means that the relay is not active
Low setpoint means that the relay is triggered by a decreasing measurement.
High setpoint means that the relay is triggered by an increasing measurement
“HOLD” active means that there is maintenance activity in progress so the
measurement is not live.
For *S3 There is the extra possibility to set up for a wash controller.
For *S4 There is the extra possibility to set up for “FAIL” indication.
Digit “Y” sets the control action:
Process alarm is a simple On/Off trip controlled by the high/low setpoint.
Proportional duty cycle control has a pulse width modulation for proportional
dosing with solenoid valves.
Proportional frequency control is used for controlling electrically positioned
valves.
Temperature alarm is an On/Off trip on the measured temperature.
Digit “Z” sets the control parameter:
With or without “integral” action.