Configuring a time dosing cycle – Burkert Type 8619 User Manual

Page 62

Adjustmentandcommissioning

If the system becomes unstable, the "TV" value set is too high: reduce it as quickly as possible.

X0: Enter the working point of the output, from 0 to 100%.
LIM- and LIM+: Some actuators (proportional solenoid valves) work on a reduced range (e.g. 40 - 80%); the
parameters "Lim-" and "Lim+" are used to match the working range of the actuator with that of the 8619: see
Figure 49.
STATE OFF: When scaling of the output is configured using the parameters "Lim-" and "Lim+", the parameter
"STATE OFF" is used to guarantee the output setting to 0% or 100% to prevent a permanent command sub-
sisting on the actuator terminals.

∆ = "state off" x ("Lim+" - "Lim-")

i.e. a proportional solenoid valve operating between a command of 40% and 80%.

Then set parameters "Lim-" = 40% and "Lim+" = 80%

If "state OFF" = 2%, then ∆ = 2% x (80 - 40) = 0.8%

Therefore, when the actual output is below 40 + 0.8 = 40.8%, the command switches to 0% and when the
actual output is above 80 – 0.8 = 79.2%, the command switches to 100%.

100%

80%

40%

∆

Theoretical output
calculated

Fx: (CMD)

Lim+ = 80%

Lim- = 40%

Figure 49 :

Example of "Lim-", "Lim+" and "State OFF" parameters setting

8.10.15. configuring a time dosing cycle

This function is available as an option. See chap. 8.10.4.

It is used to add one or two products to the process, either at regular intervals ("DoMode" = "Period"), or
according to the days of the week ("DoMode" = "Week"). The quantity added is proportional to the time open
(programmable) of the command unit.

Type 8619

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