phytron
35
MA 1235-A016 EN
6.5.2 RS 485 Interface
When up to 16 MCC-2 are connected together in bus mode (RS 485/4-wire), an individual
address has to be set on the rotary switch ‚Address’ for each MCC-2.
A USB/RS 485 converter has to be used for USB connection to the PC.
Alternatively, a PC with RS 422- or RS 485/4-wire interface can be the master.
Fig. 23: X5 Com: connector, type A (DIN IEC 61076-3-107)
PC with RS 485/4-wire- or RS 422 interface
↔
RS 485 bus
The figure below shows the RS 485 bus connection to MCC-2 by a RS 422 or RS 485/4-
wire interface on PC.
Fig. 24: Connection PC (RS 422/485 interface
)
MCC-2 (RS 485 interface)
Remark:
•
It is not necessary to use an external bus termination connector for RS 485 bus,
because the bus termination resistors are already built-in the MCC-2.
•
In the RS 485 bus mode the PC is the master. Therefore an interface type RS 422
or RS 485/4-wire is necessary.
The complete bus only operates, if all devices are supplied at X9 connector. If
the supply voltage is disconnected on one MCC-2, all following devices on bus
are without communication.
