Yokogawa EXA DC402 Dual-Channel Conductivity Analyzer - Manual (Page 45)

IM 12D08E02-01E
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 *S3, *S4
and 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 *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:
Alarm on main process
Control on main process
(Main process means conductivity/resistivity depending on the setting of
service code 01).
Code Display Function Function detail X Y Z Default values
Contacts
40
*S1 Relay 1 settings Off 0 2.0.1
Low setpoint 1
High setpoint 2 High
Note: Main process “HOLD” active 3
means cond. or resist. Process alarm 0 Alarm
whichever is set in Proportional duty cycle control ** 1
code #1 Proportional frequency control ** 2
PI duty cycle ** 3
PI pulse freq. ** 4
USP contact 5
Calculated value 0
Meas cond/res. value cell 1 1 Cell 1
Meas cond/res. value cell 2 2
Meas temp. value cell 1 3
Meas temp. value cell 2 4
Meas temp. T1-T2 5
41 *S2 Relay 2 settings Off 0 1.0.1
Low setpoint 1 Low
High setpoint 2
Note: “HOLD” active “HOLD” active 3
relay contact is used Process alarm 0 Alarm
to indicate when the Proportional duty cycle control 1
measuring mode is Proportional frequency control 2
interrupted PI duty cycle ** 3
PI pulse freq. ** 4
USP contact 5