B&R Panel PC 2100 User Manual page 202

Technical data
2.3.5.8.3.1 COMA serial interface - Pinout
Serial interface COMA is referred to as IFx on the system unit.
Type
UART
Transfer rate
Bus length
Pin
1
2
3
4
5
6
7
8
9
10
1) The interfaces, etc. available on the device or module have been numbered as such for the purpose of clear differentiation. This numbering may deviate
from the numbering used by the respective operating system, however.
2) This interface (if available) is enabled automatically in BIOS as COMA with default I/O address 3F8h and IRQ 4.
3) This interface is referred to as IF7 in Automation Studio / Automation Runtime.
Operating COMA as an RS485 interface
The pins of the RS422 default interface (7, 8, 9 and 10) must be used to operate in this mode. Pins must be
connected as shown.
The RTS line must be switched by the driver for each transmission or reception; there is no automatic switch-
back mechanism.
The voltage drop resulting from long cable lengths can result in greater potential differences between the bus
stations, which can hinder communication. This can be improved by running the ground wire with the others.
202
Serial interfaceCOM A - IFx
RS422/RS485
RS422/RS485, electrically isolated
16550-compatible, 16-byte FIFO
Max. 115 kbit/s
Max. 1200 m
Assignment
-
-
-
-
-
COM GND
TXD
TXD\
RXD
RXD\
Table 204: 5ACCIF01.FSS0-000 - Interface COMA
9
RXD
7
TXD
10
RXD
8
TXD
Figure 110: RS232/422/485 interface - COMA operation in RS485 mode
1)2)3)
10-pin, male
1 3 5
2 4 6
DATA
DATA
Panel PC 2100 user's manual V1.17
7 9
8 10