Thermo Scientific ALPHA DO 2000 PG POLAROGRAPHIC DISSOLVED OXYGEN CONTROLLER TRANSMITTER, Manual

Page: 41 / 56

Instruction manual
Alpha
DO 2000
7.2 Manual Relay Mode
In manual relay mode, you can manually turn “on” and “off” the control
devices connected to Relay A, Relay B or Wash relay.
1. While in Measurement mode press MODE key .
2. The display prompts you to enter the security code. Press
▲
or
▼
key to set
security code to “22”.
3. Press ENT key . The Manual relay mode is activated and the relay mode LED
“Manu” lights.
Î
NOTE: Pressing ENT key at a value other than “22” will cause the transmitter
to revert to Measurement mode, and the relays will remain in
automatic mode.
4. Press REL key to select either Relay A, Relay B or Wash relay. The
corresponding LED (A, B, or W) turns to red.
The manual control options now available depend on the control type (limit,
pulse frequency, or pulse length) you selected and set in section 6.5.
31.0
MEAS
%
If you selected Limit control: The display shows the
current measured value (in upper display) and “OFF” or
“ON” (in lower display) depending on the relay status of
the currently selected relay.
If you selected Pulse length control: The display shows
the current measured value (in upper display) and the on
time (in lower display) as a percentage of the current
duration set in the CNTR sub-function in setup mode.
If you selected Pulse frequency control: The display
shows the current measured value (in upper display)
and the pulse frequency (in lower display).
31.0
MEAS
%
31.0
MEAS
%
Press the
▲
or
▼
key to change the Relay on/off status, pulse length, pulse
frequency or wash function. The relay status LED at the right of the transmitter will
also change from Red to Green.
Î
NOTE: Note: If you wish to manually change the status of relays, press the REL
key at this point and repeat step 5 for the other two relays. The relay(s)
will remain under manual control while you are setting a relay.
Press the MODE key to return to Measurement mode. The relays are now back to
automatic control.
33