Watson-Marlow 520Du User Manual
Page 75
The pump is automatically switched into auto-restart mode and displays the !
icon. The only keys active are STOP, AUTO/MAN, DIRECTION and START
(available only as an extended keypress to toggle keypad lock). UP and DOWN
keys are available if manual scaling has been set (see below).
If the remote direction input is active and the direction-enable link is applied,
the DIRECTION key is disabled. If keypad lock is set, only STOP and START
(available as an extended keypress to toggle keypad lock) are active.
The pump displays whichever of four auto running screens is appropriate
according to the previously selected auto mode - 4-20mA or 0-10V with or
without scaling in place.
The auto running screens display four pieces of information: the speed at which
the pump rotates after receiving a low signal on Analogue 1 (4mA or 0V); the
speed at which the pump rotates after receiving a high signal on Analogue 1
(20mA or 10V); the set speed (that is: the speed at which the pump is current-
ly rotating according to the analogue speed signal and the analogue scaling sig-
nal if scaling is set); and the flowrate in the units selected (see 18.8 Flow
units). The scaling percentage is also displayed if it is set.
If manual scaling is enabled using the Setup menu (see 18 Setup), the scaling
percentage can be adjusted between 0% and 100% using the UP and DOWN
keys.
The pump responds to remote digital inputs. If the run / stop input stops the
pump, the bottom line of the auto running screen shows “Remote stop”. When
it starts the pump again, this will disappear and the pump returns to normal
running mode.
If the pump is stopped because a leak is detected, the screen displays “LEAK
DETECTED. Check and reset, then press Stop”. See 25.1 Error codes.
The remote status outputs operate fully.
How to get out of auto operation
If you entered auto operation by pressing the AUTO/MAN key and selecting
Analogue, leave auto operation by pressing the AUTO/MAN key and choosing
one of the three options: Analogue, Manual and Network. Use the UP and
DOWN keys to make a selection and press ENTER to confirm.
Selecting Manual returns the pump to manual operation. Using this method
of changing from AUTO/MAN, the pump retains the set speed from its pre-
vious operation in manual mode in a stopped condition. See 14 Manual
operation.
Selecting Network puts the pump into network (RS232) mode. See 24
Network control and operation.
Selecting Analogue returns the pump to analogue mode. It responds to the
analogue signal as soon as this is done and shows the “AUTO” icon.
If you entered auto operation by making the remote auto / manual input go
high, leave auto operation by making the remote auto / manual input go low
(0V). The pump returns to manual operation and retains the set speed and run
status from its previous operation in analogue mode.
Watson-Marlow 520Du User Manual
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