Authorised people can enter in the
‘Control variable’ field from
where the system is to obtain its control variable:
n
‘Internal’ :
Manual specification of the control variable on the touch panel
n
‘External’ :
Specification of the control variable via a standard signal inter‐
face 0/4-20mA. The type of 0-20mA or 4-20mA interface can
be selected in the
‘Sensor type’ field.
10.4.4.1.1
"Internal" operating mode
‘Operation
è
Operating mode
è
”Internal” operating mode
è
...’
The control variable can be set manually in
‘Internal’ operating
mode.
The
‘Control range’ indicates what percentage of the nominal
output is generated with a control variable of 100%.
Nominal output of the system 140 g/h with a control variable of
100% and a control range of 100%.
With a control range of 80%, a maximum of 0.8 * 140 g/h = 112
g/h is generated.
Control range in %
10.4.4.1.2
"External" operating mode
‘Operation
è
Operating mode
è
”External” operating mode
è
...’
In the
‘External’ operating mode, the control variable is specified
via a standard 0/4-20 mA signal interface. The type of 0-20mA or
4-20mA interface can be selected in the field underneath. The
system switches off so that the specification can be monitored and
possibly corrected. Thereafter the system must be started man‐
ually using the
[START] key on the touch panel.
The
‘Control range’ indicates what percentage of the nominal
output is generated with a control variable of 100%.
Nominal output of the system 140 g/h with a control variable of
100% and a control range of 100%.
With a control range of 80%, a maximum of 0.8 * 140 g/h = 112
g/h is generated.
Control range in %
10.4.4.1.3
"Manual" operating mode
If
[Manual] is pressed in the next display, you can switch on
(green) and switch off (grey) the valves shown on the display. This
function is used for maintenance or test purposes.
Pressing
[Automatic] means that the PLC Programmable Logic
Controller takes back control of the valves.
10.4.4.2
Times
‘Operation
è
Times
è
...’
Operation
54