2
0
1
8
-0
7
56
Channel-Related Parameters for the Valve Coupler Modes
8.4.4
Cyclic Function Test (Partial Stroke Test)
You can activate a cyclic function test for each channel. Use this function test, e. g., if you need
to regularly monitor a valve for correct functioning that is hardly triggered.
The factory setting of the Cyclic Function Test parameter is "OFF". Set the parameter to "ON".
Go to the Period of Cyclic Function Test parameter in order to specify the intervals during which
to carry out the test.
After the specified time interval elapsed, the valve is controlled
–
for a short period
–
into the
position opposite to the current position, until the relevant final position sensor indicates the
breakaway of the valve. Next, the valve is controlled back immediately. That means, the test
does not interfere with any process that is running in the meantime.
This procedure is repeated periodically.
Valve time monitoring remains active during the tests. The indication that the breakaway time,
measured during the test, is exceeded or fallen below, is given via the CB_D variable. The
CB_D variable also detects and indicates that the valve is blocked. For more information on the
variable, see chapter 4.3.1.
