WinSystems PCM-VDX-2-512, Product Manual

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140808 PRODUCT MANUAL PCM-VDX-2-512 23
Pin RS-232 RS-422 RS-485
1 DCD N/A N/A
2 RX TX+ TX/RX+
3 TX TX- TX/RX-
4 DTR N/A N/A
5 GND GND GND
6 DSR RX+ N/A
7 RTS RX- N/A
8 CTR N/A N/A
9 RI N/A N/A
All serial ports are configured as Data Terminal Equipment (DTE). Both the send and receive registers of each port
have a 16-byte FIFO. All serial ports have 16C550-compatible UARTs. The RS-232 transceivers have charge pumps to
generate the plus and minus voltages so the PCM-VDX-2-512 only re5V to operate.
Each port is setup to provide internal diagnostics such as loopback and echo mode on the data stream. An independent,
software programmable baud rate generator is selectable from 50 through 115.2 kbps. Individual modem handshake
control signals are supported for all ports.
COM1 and COM2 Configuration Options in BIOS
1. RS-232 Mode
2. RS-422 Mode with RTS transmitter enable
3. RS-422 Mode with auto transmitter enable
4. RS-485 Mode with RTS transmitter enable
5. RS-485 Mode with RTS transmitter enable and echo back
6. RS-485 Mode with auto transmitter enable
7. RS-485 Mode with auto transmitter enable and echo back
COM1, COM2 [DB9 Male]
Mode(s) Configuration Note
2, 4, 5 Require the RTS bit (MCR Bit 1) to be set in order to transmit.
3, 6, 7 Require TX/RX(300) termination on one node.
4 Requires the RTS (MCR Bit 1) be de-asserted in order to receive.
* Each of the RS-422/RS-485 modes allow for jumper selection of transmit and/or receive termination and
biasing resistor(s). An 8-pin configuration jumper is provided for each port.
COM1 = JP4
COM2 = JP2
Termination Resistors
1 3 5 7
2 4 6 8
□ □ □ □
□ □ □ □
RS-422 Termination and Biasing Resistors
TX (100): Places a 100Ω Resistor across the TX± pair 7-8
RX (100): Places a 100Ω Resistor across the RX± pair 1-2
TX/RX(300):
Places a 100Ω Resistor from +5V to TX+ 5-6
Places a 100Ω Resistor between TX± 7-8
Places a 100Ω Resistor from Ground to TX- 3-4
RS-485 Termination and Biasing Resistors
TX (100): Places a 100Ω Resistor across the TX/RX± pair 7-8
TX/RX(300):
Places a 100Ω Resistor from +5V to TX/RX+ 5-6
Places a 100Ω Resistor between TX/RX± 7-8
Places a 100Ω Resistor from Ground to TX/RX- 3-4