Endress+Hauser Liquiline CM442R - Page 80

Operation Liquiline CM442R/CM444R/CM448R
80 Endress+Hauser
Chlorine control with feedforward control
Utilize the advantage of the effectively wear-free control with binary outputs versus a control
system with relay. It is possible to achieve virtually continuous dosing using a dosing pump with
higher input frequency through pulse frequency modulation (PFM).
1. Connect the proximity switch INS from assembly CCA250 to a digital input of the DIO
module. Configure a controller in the software and for the "Controller Enable" function select
the binary input to which the proximity switch is connected. Leave the "Signal type" in the
inputs menu at the factory setting "Static signal" as the selected input.
2. Connect the flowmeter value to the second input of the DIO module. Set the "Signal type" for
this input to "PFM" in the inputs menu and select the corresponding measured value.
 You can now use this input in the controller menu as the disturbance variable for your
controller
1)
. For this purpose, in the "Disturbance variable" submenu select the binary
input to which you have connected the flow measured value as the "Source of data".
3. You can activate a dosing pump through PFM via a digital output of the DIO module. In the
outputs menu, set the "Signal type" of the corresponding binary output to "PFM" and use the
previously configured controller as the "Source of data." Take the direction of action of your
dosing into account by setting the "Actuator type" correctly.
You must make additional settings in the controller menu to fully customize the control to
your process conditions.
CM44xR as cleaning master
1) An activation code, Order No. 71211288, is necessary for the "feedforward control" function.
a0020124
Fig. 62: Example of a central cleaning control
1 External cleaning trigger at the binary input
2 Transferring the external hold over binary output to other measuring devices without connected cleaning functions
3 Transferring the cleaning trigger over a binary output to other self-cleaning measuring points