Since the characteristics of machines vary considerably, no one PLC can satisfy all machine control requirements. Therefore, Siemens provides PLCs of varying sizes and capabilities. The Siemens SIMATIC family’s of PLCs include the 505, S5, and the S7-200, S7-300, and S7-400.
Depending on the application, PLCs, operator panels, and control components may require a regulated power supply. The SITOP power supply provides a regulated source of 24VDC power and the ability to ride through momentary power dips between 3 to 10 ms. Longer ride through times can be achieved with an optional back up module which can provide up to 100 ms at 40 amps. An optional DC UPS (Uninterruptable Power Supply) module and an external battery are also available.
SITOP power supplies meet standards of agencies worldwide. They are suitable for use on worldwide networks and require no fusing on the secondary. Models are available up to 40 amps and SITOP can be used 100% of the rates output current.
An S7-200 PLC is mounted in a machine’s control panel. The manufacturer of the machine has chosen to use field devices that require 24 VDC power. The power for the field devices and the PLC is provided by SITOP power supplies, one of which is shown adjacent to the S7-200.