| At the digital outputs, each of the ground connections of the loads is connected with a | |
| eparate cable for each load to the central terminal block. With correct wiring, the supply current flows from the power supply 2L+ via terminal 29 to the | |
module. In the module, the current flows via the output driver and exits the module via
terminal 40.I | |
f a wire break occurs on the first ground cable from the central terminal block to terminal 30,
the module can continue to operate without restrictions, as it is still connected to the ground
via the second cable from the central terminal block to terminal 40.If a wire break occurs on the second ground cable from the central block terminal to
terminal 30, the module can continue to operate without restrictions, as it is still connected to
the ground via the first cable from the central terminal block to terminal 40gure 4-16 Current flow upon interruption of both ground cables
If a wire break occurs on the first and on the second ground cable from the central terminal
block to the terminals 30 and 40 of the module, a malfunction occurs on the module. Both
ground connections of the module are interrupted.
The supply current flows from the power supply 2L+ via terminal 29 to the module. In the
module, the current flows via the output driver into the parasitic diode and exits the module
via the output terminal, e.g. as shown in the figure via terminal 27. The supply current
therefore flows via the connected load. The internal supply current is typically 25 mA.
WARNING
Interruption of both ground cables
If the ground terminals 30 and 40 are interrupted, the following incorrect response can
occur:
The activated outputs, which are switched to high, start to switch back and forth between
high and low. If the load connected at the output is sufficiently small, the output is
continuously activatedTerminals 30 and 40 are connected in the front connector and only routed with one cable to
the central terminal block. If this cable breaks, terminals 30 and 40 are no longer connected
to the ground. The module's supply current flows out via the output terminal.If a break occurs in the common cable, the current of the outputs flows via terminal 30 to the
module and via terminal 40 to the central terminal block. The current flows via the module.
WARNING
Current flow with faulty wiring
If a break occurs in the common cable, the current can be very high, depending on the
plant, and lead to the destruction of the moduleThe figure below shows the current flow with correct wiring when a potential difference exits
between the grounding pointsEquipotential bonding occurs via terminals 30 and 40. When a potential difference exists
between the grounding points FE1 and FE2, the compensating current flows via terminals 30
and 40.
WARNING
Current flow with faulty wiring
In the event of a potential difference, the current can be very high, depending on the
potential conditions, and lead to the destruction of the module.You connect the encoder signals, the digital input and output signals and the encoder
supplies to the 40-pin front connector of the digital on-board I/O. For information on wiring
the front connector, creating the cable shield, etc., refer to the S7-1500, ET 200MP The 24 V encoder signals are designated with letters A, B and N. You can connect the
following encoder types:
● Incremental encoder with signal N:
Signals A, B and N are connected using the correspondingly marked connections.
Signals A and B are the two incremental signals, phase-shifted by 90°. N is the zero mark
signal that supplies a pulse per revolution.
● Incremental encoder without signal N:
Signals A and B are connected using the correspondingly marked connections. Signals A
and B are the two incremental signals, phase-shifted by 90°.
● Pulse encoder without direction signal:
The count signal is connected to the A connection.
● Pulse encoder with direction signal:
The count signal is connected to the A connection. The direction signal is connected to
the B connection.
● Pulse encoder with up/down count signal:
The up count signal is connected to the A connection. The down count signal is
connected to the B connection.
You can connect the following encoders or sensors to the A, B and N inputs:
● Sourcing output:
The encoder or sensor switches the A, B and N inputs to 24 V DC.
Note
External load resistance
Note that, depending on the characteristics of the signal source, effective load and height
of the signal frequency, you may require an external load resistance to limit the fall time
of the signal from high level to low level.
The specifications/technical data of the signal source (e.g. sensor) are decisive for the
configuration of such a load resistance.
● Push-pull:
The encoder or sensor switches the A, B and N inputs alternately to 24 V DC and to
ground MThe digital inputs are logically assigned to the high-speed counters (HSC). For information
on the possible assignment of the on-board I/O inputs to the high-speed counters, refer to
the table Interconnection overview of the inputs (Page 98). Up to two digital inputs are
available for each high-speed counter (HSC DI0 and HSC DI1). You can use the digital
inputs for the gate control (Gate), synchronization (Sync) and Capture functions.
Alternatively, you can use one or more digital inputs as standard digital inputs without the
functions mentioned and read the signal state of the respective digital input using the
feedback interface.
Digital inputs that you do not use for high-speed counting are available for use as standard
DIs.You set the digital input addresses used by the high-speed counters (HSC) and the
assignment of A/B/N, DI0, DI1 and DQ1 signals in STEP 7 (TIA Portal). You can enable and
configure each HSC when you configure the compact CPU.
The compact CPU assigns the input addresses for the A/B/N signals automatically according
to the configuration.
You specify the input addresses for DI0 and DI1 according to the table Interconnection
overview of the inputs (Page 98). The interconnection produces a direct connection of the
HSC to an input of the on-board I/O. The high-speed counter then uses this input as HSC
DI0 or HSC DI1 ([DI] symbol). The [DI] symbols in the table identify the input addresses for
HSC DI0 and HSC DI1 that are offered for selection in the hardware configuration.You can find an overview of the options for interconnecting the inputs of the front connectors
X11 and X12 in the section Interconnection overview of the inputs (Page 98).
Digital outputs HSC-DQ0 and HSC-DQ1
Two digital outputs are available for each high-speed counter. Digital output HSC-DQ0 is a
logical output that cannot be interconnected with a digital output of the on-board I/O. Digital
output HSC-DQ0 can only be used via the user program. HSC-DQ1 is a physical output that
can be interconnected with a digital output of the on-board I/O.
The digital outputs are 24 V sourcing output switches relative to M and can be loaded with a
rated load current of 0.1 A. The outputs used as standard outputs have a rated load current
of 0.5 A. The digital outputs are protected against overload and short-circuit.
Note
It is possible to directly connect relays and contactors without external wiring. For information
on the maximum possible operating frequencies and the inductance values of the inductive
loads at the digital outputs, refer to the Technical specifications section.
The section Interconnection overview of the outputs (Page 99) provides an overview of
which digital outputs you can interconnect to which high-speed counters. Digital outputs to
which no high-speed counter is interconnected can be used as standard outputs. The
maximum output delay of each digital output used as standard output is 500 µs.
Wiring
4.3 Terminal and block diagrams
CPU 1511C-1 PN (6ES7511-1CK00-0AB0)
96 Manual, 09/2016, A5E35306259-AB
Shielding
Note
When you use digitalWhen you use digital inputs/outputs with technology functions, i.e. interconnect high-speed
counters with the inputs/outputs, you must use shielded cables and the infeed element for
shielding.
Reference
For more information on configuring the inputs of the high-speed counters, refer to the
S7-1500, ET 200MP, ET 200SP Counting, measurement and position detection If you configure the memory of the outputs of the CPU as pulse generators (for PWM or
PTO), the corresponding addresses of the outputs are removed from the memory of the
outputs. You cannot use the addresses of the outputs for other purposes in your user
program. When your user program writes a value to an output that you are using as a pulse
generator, the CPU does not write this value to the physical output.
Assignment of the PWM addresses of the outputs
The section Interconnection overview of the outputs (Page 99) provides an overview of
which digital outputs you can interconnect to which PWM channels.
You assign the digita
