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PCMCIA-RS485/2 connected to RS422
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AGV
Nov 5, 2004, 7:05:45 AM11/5/04
to
I want to connect PCMCIA-RS485 (DB9) with a RS-422 board (DB25) in
other computer. Which connectors and cable I need?
other computer. Which connectors and cable I need?
Chris Rake
Nov 5, 2004, 8:39:01 AM11/5/04
to
You will need to determine the pinout of the other board, and then
connect TX+ to RX+, TX- to RX-, etc. This may require a custom cable.
connect TX+ to RX+, TX- to RX-, etc. This may require a custom cable.
AGV
Nov 8, 2004, 2:54:56 AM11/8/04
to
I have built a 4-wire cable
TX+ -> RX+
RX+ -> TX+
TX- -> RX-
RX- -> TX-
I send a frame from the RS-422 board but receive nothing in the NI
RS-485.
I only want to see the bytes belonging to that frame using a simple
tool like TALBreakOut.
Is necessary to perform some configuration in the board?
TX+ -> RX+
RX+ -> TX+
TX- -> RX-
RX- -> TX-
I send a frame from the RS-422 board but receive nothing in the NI
RS-485.
I only want to see the bytes belonging to that frame using a simple
tool like TALBreakOut.
Is necessary to perform some configuration in the board?
AGV
Nov 8, 2004, 9:59:17 AM11/8/04
to
How can I configure PCMCIA RS-485/2 to work with the RS-422 protocol?
If I need a clock signal, which pin is used as clock?
Chris Rake
Nov 8, 2004, 10:20:51 AM11/8/04
to
RS-485 will work with RS-422 without any changes as the voltage levels
are essentially the same. However this is an async port (driven by a
UART), so no clock is available.
are essentially the same. However this is an async port (driven by a
UART), so no clock is available.
AGV
Nov 8, 2004, 12:14:11 PM11/8/04
to
OK, I must work in ASYNC mode.
So, I have configured both boards in ASYNC mode with the following
parameters
Bits per second = 9600
Data bits = 8
Parity = None
Stop Bits = 1
Flow Control = None
So, I have configured both boards in ASYNC mode with the following
parameters
Bits per second = 9600
Data bits = 8
Parity = None
Stop Bits = 1
Flow Control = None
Then, I send a frame of 1 byte but receive a different value in 2
bytes (the second is 00):
SENT ----- RECEIVED
3 ----- 7E00
4 ----- 1F00
5 ----- 7D00
Do you guess what can be the problem?
Chris Rake
Nov 8, 2004, 12:26:48 PM11/8/04
to
Are you using the PCMCIA-485 as a sync serial port? Or is this a VISA
setting?
setting?
AGV
Nov 9, 2004, 3:16:05 AM11/9/04
to
I think that as a sync serial port because I only configure the
following:
- Device Manager > Ports(COM & LPT)
- Double click the Port
- Port Settings: 9600 / 8 / None / 1 /None
- Advanced: Transceiver Mode -> 4 wire
following:
- Device Manager > Ports(COM & LPT)
- Double click the Port
- Port Settings: 9600 / 8 / None / 1 /None
- Advanced: Transceiver Mode -> 4 wire
AGV
Nov 9, 2004, 8:50:08 AM11/9/04
to
Does the PCMCIA-485 uses NRZ encoding?
Chris Rake
Nov 9, 2004, 10:54:58 AM11/9/04
to
The PCMCIA-485 is a UART-based device. The data frame is identical to
that of a built-in RS-232 port, the only difference being the
transceivers and voltage levels.
that of a built-in RS-232 port, the only difference being the
transceivers and voltage levels.
Chris Rake
Nov 9, 2004, 12:06:31 PM11/9/04
to
The PCMCIA-485 cards transmit and receive UART-framed data. For each
byte sent, the frame will be:
byte sent, the frame will be:
Start bit, data, parity (optional), and stop bit.
There is no sync clock, and the UART resyncs on the start bit of each
frame. A summary of the serial communication, including voltage
levels and the data frame details, can be found at:
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