12
= Key1
= Key 2
= Key 3
= Max. value or consumption = Min. value or supply
Serial interfaces
RS485 (Option)
Terminal resistors
All devices are connected in bus structure (line). In
a segment, up to 32 participiants can be connected.
At the beginning and at the end of a segment the
cable is terminated with resistors. In the UMG505
these terminal resistors can be activated with
pluggable bridges.
For more than 32 participiants a repeater must be
used (amplifier), to connect the single segments.
Protection
For connections via RS485 interface, a twisted and
protected cable must be used. To reach the required
protection, the shield must be connected to housing
parts at both ends of the cable over a wide surface.
Cable type
Unitronic LI2YCYCTPJ2x2x0,22 (Lapp Kabel)
Cable length
1200m at baudrate 38,4k.
RS232 (Option)
The maximum distance between two devices with
RS232 depends on the used cable and the baud-
rate. The normal distance for a baudrate of 9600
Baud should not exceed 15 up to 30 meters. The
allowed load must be bigger than 3kOhm, The
capacitive load, caused by the transmission cable,
is limited to 2500pF.
Diagr. Connection of two devices with RS232
interface
Terminal resistor
Device with RS485 interface
Diagr. Bus structure with terminal resistors on both
sides.
Converter
RS485/RS232
PSW505
Protocol 01 = MODBUS
UMG505
UMG505
RS232
RS485
RS232
RS485
RS232
RS232
Protocol 02 = Modem
Customer’s software
Modem
RxD TxD on
Modem
RxD TxD on
UMG505
Zero modem cable
Protocol 01 = MODBUS
PSW505
UMG505
RS232
RS232
