Octagon PC-500, Руководство пользователя

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5-6
Serial ports PC-500 user’s manual
Note See the Accessories appendix for mating information on COM3 and
COM4.
COM5
COM can be configured either as an industrial 2-wire RS-485 port or a
2-wire TTL serial port. COM5 uses the RTS pin to enable or disable the
RS-485 transmit/receive function. That is, a logic ‘1’ in bit position 1,
register offset 4, will enable the transmitter function and disable the
receiver function. A logic ‘0’ in bit position 1, register offset 4, will
disable the transmitter function and enable the receiver function.
The interrupt, IRQ15, for COM5 is logically OR’d with COM3 and
COM4. Interrupt routing for COM5 is configured through the interrupt
routing matrix. COM5 is located at J17. For more information, see the
COM3 through COM5 interrupt/status port section in this chapter.
Table 5-10 Available addresses for COM5 (IRQ 5 default, routable)
Address IRQ
320h IRQ15*
* = default, routable
Table 5-11 COM5: J17, RS-485 or TTL interface
For RS-485 interface For TTL interface
Pin 1 RS-485+ Pin 1 TTL RD
Pin 2 TxD Pin 2 TxD
Pin 3 Gnd Pin 3 Gnd
Pin 4 RS-485– Pin 4 NA
W1[1-2][3-5][4-6]* W1[2-4][5-6]
* = default
Note See the Accessories appendix for mating information on the COM5
connector.
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Null modem cable
The PC-500 requires an RS-232 null modem cable to interface to your
desktop PC.
Mating receptacle
Use a VTC-20F cable to connect either COM1 and COM2, or COM3 and
COM4 to external serial equipment. The P2 and P3 connectors are
DB-9 female connectors which plug directly into a 9-pin PC serial cable.
When interfacing the PC-500 to your desktop PC, you must use a null
modem adapter.