2 General Device Description
The protocol converter consist of a main board and a power supply board, with
the DC/DC converter which generates all internal voltages.
The main board has an 80C188 microprocessor. It has an internal timer, interrupt
and DMA controllers, and therefore requires only a few external components.
The computing power is sufficient to process even large quantities of data. In ad-
dition, the 16-bit processor facilitates efficient software development in a high
level language. The firmware and the configuration data are stored in a flash
EPROM. This can be programmed in the circuit and retains its data even when
the power supply is switched off.
The serial interfaces are realized by the SCC controller AM85C30 and the ASIC
SPC3. For the connection of a device with the converter there is a non-isolated
interface wich can be configured as RS232, RS422 or RS485-type. The second
isolated interface is designed for the PROFIBUS-DP.
The correct function of the protocol converter and its internal power supply are
monitored by a watchdog circuit with the MAX 705 component. In the case of er-
ror, this triggers a reset on the processor.
The internal power supply is provided by a switching controller. Its input voltage
is filtered through a current compensated annular core reactor and filter capaci-
tors. A transient diode is provided as overvoltage and reverse polarity protection.
In the case of a fault, the internal semiconductor fuse switch off until the fault
disappears. In addition, there is a charging capacitor which blocks voltage drops
such as those which occur on switching of contactors.
Valid operation and an error state from the serial interfaces are displayed by
LEDs.
Block diagram of the protocol converter PKV 30-DPS
General device description
5
Copyright * Hilscher Gesellschaft für Systemautomation mbH * Hotline/Support: +49(0)6190/9907-99 * De:P30DPS#5E
