Instruction manual
Instruction manual  αlpha DO 2000 
33 
(c) P/PI Control only 
Proportional Range  10 to 500 % 
Integral Action Time (IAT)  0.0 to 999.9 minutes 
(c) (1) Pulse Length Control (PLC) 
Pulse Length  0.5 to 20.0 seconds 
(c) (2) Pulse Frequency Control (PFC) 
Pulse Frequency  60 to 120 pulses / minutes 
Contact Outputs  Two SPST relays 
Switching Voltage / Current / Power  Max 250VAC / Max 3A / Max 600VA 
8.3  Wash Function – Wash Relay 
Relay contact selection for active mode  Energise (EN) or 
De-energise (DEEN) 
Wash Cycle Interval  0.1 to 200.0 hours 
Wash Duration  1 to 2000 seconds 
Contact Outputs  One SPST relay 
Switching Voltage / Current / Power  Max 250VAC / Max 3A / Max 600VA 
8.4  Alarm Function – Alarm Relay 
Alarm Delay  0 to 2000 seconds 
Alarm control  Steady or fleet (pulse) 
Contact Outputs  One SPDT relay 
Switching Voltage / Current / Power  Max 250VAC / Max 3A / Max 600VA 
8.5  Transmitter Function 
(a) Current Output 1 - DO  Proportional to Dissolved Oxygen measured 
Current output selection  4 – 20mA or 0 – 20mA 
DO value for 0 or 4mA current   0 to 25 mg/l or 0 to 300 % 
DO value for 20mA current  0 to 25 mg/l or 0 to 300 % 
CU22 function  On 
- 22mA current output for over range or under range or if 
outside zoom setting 
Off 
- 0 or 4 mA current output for under range or below lower 
zoom setting 
- 20mA current output for over range or above upper 
zoom setting 
(b) Current Output 2 - Temperature  Proportional to Temperature measured 
Current output selection  4 – 20mA or 0 – 20mA 
Temperature value for 0 or 4mA 
current 
-10.0 to +125.0 
o
C or +14.0 to +257.0 
o
F 
Temperature value for 20mA current  -10.0 to +125.0 
o
C or +14.0 to +257.0 
o
F 










