Fail-Safe Modules
7.7 4 F-DO DC24V/2A PROFIsafe digital electronic module
ET 200S Distributed I/O System - Fail-Safe Modules
Installation and Operating Manual, 08/2008, A5E00103686-07
171
7.7.4
Parameters for the EM 4 F-DO DC24V/2A PROFIsafe
Parameters in
STEP 7
The table below lists the parameters that can be assigned for the F-DO module (see also
"Configuring and programming").
Table 7- 35 Parameters of the F-DO Module
Parameter
Range
Default
Type of
Parameter
Effective
Range
F Parameters:
F_destination_address
1 to 1022
is assigned
by
STEP 7
Static
Module
F monitoring time
10 to 10000 ms
150 ms
Static
Module
Module Parameters:
Behavior after channel faults*
Passivate the entire
module/Passivate the
channel
Passivate
the entire
module
Static
Module
DO channel n
Activated/deactivated Activated
Static
Channel
Readback time
1 to 400 ms
1 ms
Static
Channel
Diagnostics: Wire break
Activated/deactivated Deactivate
d
Static
Channel
* This setting is only relevant when
S7 Distributed Safety
V5.4 or higher is installed.
Readback Time Parameter
Each output channel has its own selectable readback time. This time specifies the maximum
duration of the turn off test for the corresponding channel and therefore also the readback
time for turning off the channel.
The following readback times can be set: 1 ms, 5 ms, 10 ms, 50 ms, 100 ms, 200 ms and
400 ms.
You should set an adequately high readback time if the channel involved switches high
capacitive loads. If the readback time for a controlled capacitive load is set too low, the
output channel is passivated because the discharge of the capacitance does not take place
within the turn off test.
If the readback signals are incorrect, the "short circuit" fault only causes passivation of the
output channel after the readback time has elapsed.
WARNING
With a configured readback time of ≥ 50 ms, short-circuits (cross circuits) can be
suppressed with an interference signal with a frequency > 10 Hz (50:50 duty cycle).
Short-circuits (cross-circuits) on an output of the same module will be detected.