Festo — MSE6-C2M — 2022-08b
Functions
21
5.1.4.2
Function structure
Input signal
The measured pressure change value DP2 is prepared according to the set unit pressure, Pm.8.0-8.1,
and pressure change sample time, Pm.10, parameters and can be shown as a selectable input signal in
Em.5 and/or Em.6.
Limit value monitoring
If the shut-off valve is in the blocking state, the amount of the measured pressure change is compared
with the upper pressure change limit value, Pm.15-16, parameter using a comparator. If limit value
monitoring is activated, Pm.0.6, the appropriate error/diagnostic message is output if the limit value is
exceeded.
Monitoring of parameters
The unit pressure, Pm.8.0-8.1, pressure change sample time, Pm.10, and upper pressure change
limit value, Pm.15-16, are checked for permissible values on input. In the event of an error, the
corresponding error message is output if parameterisation error monitoring is activated, Pm.0.7.
Unit
pressure
Pm.8.0-8.1
Upper
critical limit
pressure
change
Pm.15-16
Pressure
change
measurement
time
Pm.10
Monitoring
of
critical limits
Pm.0.6
Monitoring
of
parameter
Pm.0.7
Data
check
P2
pressure
sensor
Data
check
Data
check
Comparator
Diagnostics, maskable
FN25, Em.3: parameterisation error upp. critical limit
FN29, Em.2: error in parameterisation
FN29, Em.3: error in parameterisation
Selectable inputs
Em.5 / 6: pressure change DP2
Diagnostics, maskable
FN10, Em.3: upp. critical limit exceeded
Pressure change DP2
Scaling
Em.3.0:
status
shut-off
valve
Measurement
pressure
change
Fig. 11: Block diagram of the pressure change function
5.1.5
Pressure regulation and blocking function
5.1.5.1
Overview
The pressure control function and blocking function determine the current module status by evalu-
ating sampled pressure values and flow rate values. The desired outlet pressure P2 is set by control-
ling the pressure regulator and the shut-off valve accordingly.
Depending on the setting, the module works in user-controlled or automatic pressure regulation mode
and blocking function.
The shut-off valve is controlled directly in the user-controlled pressure regulation and blocking mode.
One of the various fixed values or a variable value can be set as the target pressure.
The target pressure is set to Auto Normal in the basic state in the automatic pressure regulation and
blocking function. If the flow rate falls below the set flow rate critical limit for the specified period
of time, the automatic pressure regulation and blocking function first switches to shut-off mode if
activated accordingly. After a pressure drop to the auto standby setpoint pressure, the function then
switches to pressure regulation mode with the target pressure auto standby setpoint pressure.
