he inputs have a rated input voltage of 24 V DC.
The inputs are suitable for switches and 2-/3-/4-wire
proximity switches.
Section Wiring (Page 77)
Configurable diagnostics The digital on-board I/O module is able to diagnose
errors. The module reports the diagnosed state to the
CPU using a diagnostics error interrupt. You can parameterize
the type of diagnostics channel-specifically.
Section Parameters of the digital onboard
I/O (Page 125)
Hardware interrupt You can react to process events (such as positive
edge, negative edge) through the configuration of a
hardware interrupt. Hardware interrupts can be parameterized
channel-granularly.
Section Parameters of the digital onboard
I/O (Page 125)
Section Structure of a data record
for input channels of the digital onboard
I/O (Page 176)
STEP 7 online helpThe digital on-board I/O module is able to diagnose
errors. The module reports the diagnosed state to the
CPU using a diagnostics error interrupt. You can parameterize
the type of diagnostics channel-specifically.
Section Interconnection overview of
outputs (Page 111)
Standard and high-speed outputs
Standard outputs The digital on-board I/O module has 16 standard outputs.
Section Wiring (Page 77)
High-speed outputs Of the 32 standard outputs you can also use 8 outputs
as high-speed outputs for technology functions.
Rated output voltage The outputs have a rated output voltage of 24 V DC.
Output frequencies and
output currents
Rated output current as output for standard mode:
0.5 A per channel.
As an output for technology functions, you can select
between an output current of up to 0.5 A at an output
frequency up to 10 kHz (load dependent) and a reduced
output current of max. 0.1 A at an increased
output frequency of up to 100 kHz.
Section Interconnection overview of
outputs (Page 111)The outputs are suitable for, e.g. solenoid valves, DC
contactors and indicator lights, or also for signal transmission
or proportional valves.
Driver blocks X11 The digital outputs of the digital onboard I/O X11 have
driver blocks with parasitic diodes. In principle, parasitic
diodes have an effect when switching off inductive
loads such as freewheeling diodes. The shutdown voltage
is limited to -0.8 V. Therefore, the demagnetization
of inductive loads takes longer and can be approximately
calculated using the following formula.
tau = L / R (tau= time constant, L = inductance value,
R = ohmic resistance value)
After the expiration of a period of 5 * tau, the current
has decreased in effect to 0 A due to the inductive load.
The maximum value is derived from:
tau = 1.15H / 48 Ohm = 24 ms. After
5 * 24 ms = 120 ms, the current has decreased in effect
to 0 A.
For comparison: With standard modules, inductive
shutdown voltage is limited, for example, to Vcc -53 V
(supply voltage – 53 V), which causes the current to
decrease to 0 A after about 15 ms.
Section Terminal and block diagram
of the digital on-board I/O (Page 90)
Driver blocks X12 The driver blocks of the outputs from the digital inboard
I/O X12 have no freewheeling diodes.
The cut-off voltage is -29 V. Inductive loads are therefore
demagnetized faster than for X11.
If ground is interrupted, no unwanted current flows
through the digital outputs to the ground.You can use technology and standard functions at the same time, provided the hardware
allows this. For example, all the digital inputs not assigned to the counting, measuring or
position detection or PTO technology functions can be used as standard DI.
Inputs to which technology functions are assigned can be read. Outputs to which technology