6.2 Interface RS-485
DANGER
Danger to life from electric shock
When establishing the voltages that exceed the specified safety extra-low voltage (according to IEC
60449 and VDE 0100), the insulating measures will be destroyed. There is a danger to life from elec-
tric shock at the communication interfaces.
► Connect only suitable devices to the bus system.
The interface with the designation “RS-485” is intended for the connection of a Pfeiffer Vacuum display
and control unit (DCU or HPU) or an external computer. The connections are galvanically safe and are
isolated from the maximum supply voltage for the electronic drive unit.
Designation
Value
Serial interface
RS-485
Baudrate
9600 Baud
Data word length
8 bit
Parity
none (no parity)
Start bits
1
Stop bits
1
Tbl. 6:
Features of the RS-485 interface
Connecting a Pfeiffer Vacuum display and control units or PC
► Use the connection cable from the control unit scope of delivery or from the accessories program.
► You can connect one external control unit to the RS-485 interface.
► You can connect a USB interface (PC) via the USB/RS-485 converter.
TC
TC
D+
D-
USB/RS485-converter
RS 485
USB
PC
PC
D-Sub
1
2
3
4
Fig. 7:
Cross-link via connection RS-485 using connection cables and accessories
1 Connection cable with RS-485
3
M12 to M12 extension cable
2 Y-connector for RS-485
4
USB RS-485 converter
Networking as RS-485 bus
The group address of the electronic drive unit is 961.
1. Install the devices according to the specification for RS-485 interfaces.
2. Make sure that all devices connected to the bus have different RS-485 device addresses
[P:797]
.
3. Connect all devices to the bus with RS-485 D+ and RS-485 D-.
Interfaces
25/52
