Siemens SIMATIC S5-90U System Manual page 513

S5-90U/S5-95U
Installation
• The closed-loop control module is plugged into a bus unit like any other input or output module
(see Chapter 3).
• With the S5-90U, a maximum of 4 closed-loop control modules can be plugged into slots 0
through 5.
• With the S5-95U, a maximum of 8 closed-loop control modules can be plugged into slots 0
through 7.
• The connections for power supply and the analog and binary output signals are located on the
terminal block of the bus unit.
• The analog and binary inputs are connected to the module with a 25-pin sub-D female
connector.
Addressing
The module is addressed like a four-channel analog module.
Operating Modes
Since transducers and sensors are directly wired to the module, the module can work independently
from a programmable controller in stand-alone operation, provided that the setpoints and the 24-V
power supply voltage are fed directly to the IP 262. This means that the module executes the control
and the output of the control value and can work alone or be controlled via the SINEC L1 by a
master unit.
Besides this, the IP 262 has its own back-up, which means that the module can continue to work
alone in the event the master CPU (e.g., S5-135U with R64) fails. It uses the last setpoint received
from the CPU or the predefined back-up setpoint. Two operating modes are possible.
• DDC-Operation (Direct Digital Control):
The control is executed entirely from the CPU and the IP only outputs the manipulated variable.
If the CPU fails, the module can continue to control independently with a predefined back-up
setpoint.
• SPC-Operation (Setpoint Control):
The module receives only the setpoint from the CPU; the control is carried out independently of
the CPU. If the CPU fails, the IP continues to control using the last setpoint received from the
CPU. It is also possible to use a predefined back-up setpoint here.
EWA 4NEB 812 6115-02b
Function Modules
16-45