AXL SE PSDI8/3
42 / 84
PHOENIX CONTACT
108928_en_02
Key:
, the following condition has not been met: both signals must be in the opposite
state before the state is changed. A diagnostic message is generated because the condition
is not met.
6.2.4
Symmetry and start inhibit
Symmetry monitoring checks the extent to which the related (filtered) inputs enter another
state simultaneously.
Symmetry is violated if the inputs indicate different states for a time greater than the value
parameterized for “symmetry”. This applies for rising and falling edges.
The symmetry violation diagnostic message is only displayed if it was enabled during
parameterization of the affected inputs.
Please observe the error detection time.
See
“Error detection time” on page 23
.
The following applies, if start inhibit due to symmetry violation is parameterized or not:
Start inhibit due to symmetry violation is disabled
– The symmetry violation message does
not
result in the transmission of the safe state.
– The message must be acknowledged.
– However, the current status of the inputs is
always
displayed in the process data image
of the inputs.
Start inhibit due to symmetry violation is enabled
– The symmetry violation message results in the transmission of the safe state.
– The message must be acknowledged.
–
Following acknowledgment
, the current status of the inputs is displayed in the pro
-
cess data image of the inputs.
IN0_CH1
Signal sequence at input 0, channel 1
IN0_CH2
Signal sequence at input 0, channel 2
IN0 (CH1/CH2)
Safety-related signal for 2-channel input 0, channel 1, and channel 2 at
the controller
For examples and further information on error detection and error messages, please refer
to the following sections:
–
“Connection examples of safe inputs” on page 45
–
“Errors: messages and removal” on page 67
Symmetry violation can also be triggered by a cross-circuit.
See
“Connection examples of safe inputs” on page 45
.
