Festo — MSE6-C2M — 2022-08b
Parameterisation
89
9.6.2
Example of pressure drop monitoring
Every system must be set individually. The sample values are only intended as general orientation.
Recommended procedure for determining the upper critical limit pressure change and pressure
change sample time parameters
1. At output pressure setpoint P2, Am.2, set the parameterised setpoint pressure value auto normal,
Pm.21-22. Switch the shut-off valve at the shut-off valve control output to the pressurise state,
Am.0.1 = 0. Activate the user-controlled pressure control function and blocking function operating
mode at the auto-user control output, Am.0.1 = 0.
2. Set the pressure change sample time parameter, Pm.10.
If the system has a high pressure drop, start with a setting of 100 ms, corresponding to Pm.10 = 1.
If the pressure drop is low, increase the pressure change sample time, e.g. to 1 s, Pm.10 = 10, so
the pressure change per 1 s is displayed. Vary the parameter value until you have determined a
suitable value for the system.
3. Switch the shut-off valve to the blocking state, Am.0.1 = 1.
4. Record pressure change values as long as the output pressure is greater than the parameterised
pressure setpoint auto standby, Pm.23-24. The values are available as selectable input data in the
inputs Em.5 or Em.6. The corresponding input address must first be set in Am.1. E.g. Am.0 = 0
indicates the pressure change in both Em.5 and Em.6.
The pressure change is a signed value. When the pressure falls, the values are correspondingly
negative.
5. Generate the value of the pressure change. With positive values, accept the input value, with
negative values, reverse the sign, e.g. –10 becomes 10.
6. Determine the value of the greatest pressure change value during the blocking state.
7. Determine the greatest pressure change value in the shut-off state in terms of amount by repeat-
edly switching the shut-off valve from the pressurise to the shut-off state with the pressure
setpoint unchanged.
If you have obtained very low values, it may be wise to increase the value for the pressure change
sample time parameter, Pm.10.
