Adastra Systems NPC-486E, Руководство пользователя

Страница: 33 / 105

26
The pin-out for the secondary connector, J8, for RS-232 operation is:
Pin # Signal Pin # Signal
1 DCD 2 DSR
3 RXD 4 RTS
5
TXD
6
CTS
7
DTR
8
RI
9 GND 10 NC
11 NC 12 NC
13
NC
14
NC
RS-485 operation on the secondary port is established by writing to Data Register 0 bits 4
and 5. The pin-out for the secondary connector, J8, for RS-485 operation is:
Pin # Signal Pin # Signal
1
NA
2
NA
3 NA 4 NA
5 NA 6 NA
7
NA
8
NA
9 GND 10 NA
11 RS485 TXD + 12 RS485 TXD -
13
RS485 RXD +
14
RS485 RXD -
The port supports two channel and single channel RS-485 operation. In two channel
operation, the transmit and receive channels are separate: transmit using pins 11 & 12,
receive using pins 13 & 14. In single channel mode, the transmit and receive operations
are multiplexed using the single channel of pins 13 & 14.
Multi-drop operation requires supplemental software to control the active transmitter in
both one and two channel implementations. Application notes and technical support are
available from Adastra Systems for RS-485 multi-drop. Inquiries should be directed to
customer service.
Data Signal level
Register 0 High Low
Bit 4 Enables RS-232 Enables RS-485
Bit 5
Single channel operation Two channel operation