Parameters for the EM 4 F-DO DC24V/2A PROFIsafe
The table below lists the parameters that can be assigned for the F-DO module (see also
"Configuring and programming"
Table 7- 35
F monitoring time
Behavior after channel faults*
DO channel n
Diagnostics: Wire break
* This setting is only relevant when
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
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.
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.
ET 200S Distributed I/O System - Fail-Safe Modules
Installation and Operating Manual, 08/2008, A5E00103686-07
Parameters of the F-DO Module
7.7 4 F-DO DC24V/2A PROFIsafe digital electronic module
1 to 1022
10 to 10000 ms
Passivate the entire
1 to 400 ms
S7 Distributed Safety
V5.4 or higher is installed.