Technical data
202
Panel PC 2100 user's manual V1.17
2.3.5.8.3.1 COMA serial interface - Pinout
Serial interface COMA is referred to as IFx on the system unit.
Serial interfaceCOM A - IFx
1)2)3)
RS422/RS485
Type
RS422/RS485, electrically isolated
UART
16550-compatible, 16-byte FIFO
Transfer rate
Max. 115 kbit/s
Bus length
Max. 1200 m
Pin
Assignment
1
-
2
-
3
-
4
-
5
-
6
COM GND
7
TXD
8
TXD\
9
RXD
10
RXD\
10-pin, male
1 3 5 7
2 4 6 8 10
9
Table 204: 5ACCIF01.FSS0-000 - Interface COMA
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.
DATA
DATA
TXD
RXD
TXD
RXD
9
7
10
8
Figure 110: RS232/422/485 interface - COMA operation in RS485 mode
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.
