3 General Device Description
The Gateway consists of a basic circuit board with a power supply circuit with
DC/DC transformers in which all the required auxiliary voltages are created. The
fieldbus communication interface is based on the basic circuit board, too.
The Elan SC520 processor board is inserted into the basic circuit board. It con-
tains a built-in timer, interrupt- and DMA-Controller and thus only requires few
external modules. The computing power is adequate for processing even large
quantities of data. Furthermore, the processor ensures efficient software develop-
ment in a high level language. The firmware and the configuration data are stored
in a FLASH-EPROM. This can be programmed within the switching and retains
its data even when the operating voltage is switched off.
The proper function of the Gateway and its internal operating voltage is monito-
red by a Watchdog circuit. In the case of error it triggers a Reset at the processor.
The internal supply voltage is generated by means of a switched mode regulator.
Its input voltage is filtered via a current-transformed toroidal choke and filter ca-
pacitors. A transient diode is available as spike and polarity reversal protection.
In the case of malfunction, a semiconductor fuse switches the device down to a
low residual current until the malfunction is cleared. This means that the chan-
ging of an internal sensitive fuse is dispensed with. Besides this, a charging ca-
pacitor is available that blocks the voltage dips that occur in the switching of
fuses.
The operational readiness and an error in the communication interface are dis-
played by LEDs.
General Device Description
6
Copyright * Hilscher Gesellschaft für Systemautomation mbH * De:PKV50#2EN
