Re: Debian-Cart I/O-modem Baycom - PROBLEM

[Ray Wells <vk2tv@exemail.com.au>]

On 06/02/13 05:53, Dave Platt wrote:
>> ENG: I need help. I have a computer with two modems Baycom
>>       Debian Linux 6.0.6, Kernel 2.6.35, driver: baycom_ser-fdx
>> ENG: I use Baycom modems, connected to the I/O PCI
>>       Modems receive (Rx) channels correctly but are not suitable (not Tx)
>> ENG: And this is the configuration I/O card with the command lspci-vvv
>> 15:06.0 Serial controller: NetMos Technology PCI 9845 Multi-I/O
>> Controller (rev 01) (prog-if 02 [16550])
>>          Subsystem: LSI Logic / Symbios Logic 0P6S (6 port 16550a serial
>> card)
>>          Control: I/O+ Mem+ BusMaster- SpecCycle- MemWINV- VGASnoop-
>> ParErr- Stepping- SERR+ FastB2B- DisINTx-
>>          Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort-
>> <TAbort- <MAbort- >SERR- <PERR- INTx-
>>          Interrupt: pin A routed to IRQ 132
>>          Region 0: I/O ports at 8cf8 [size=8]
>>          Region 1: I/O ports at 8ce8 [size=8]
>>          Region 2: I/O ports at 8cd8 [size=8]
>>          Region 3: I/O ports at 8cc8 [size=8]
>>          Region 4: I/O ports at 8cb8 [size=8]
>>          Region 5: I/O ports at 8ca0 [size=16]
>>          Kernel driver in use: serial
>
>> ENG: and data from /var/log/dmesg
>> 15:06.0 Serial controller: NetMos Technology PCI 9845 Multi-I/O
>> Controller (rev 01)
>>
>> [    1.574194] Linux agpgart interface v0.103
>> [    1.574477] Serial: 8250/16550 driver, 8 ports, IRQ sharing enabled
>> [    1.576605] serial 00:06: activated
>> [    1.576953] 00:06: ttyS4 at I/O 0x108 (irq = 12) is a 16550A
>> [    1.577147] serial 0000:15:06.0: PCI INT A -> GSI 132 (level, low) ->
>> IRQ 132
>> [    1.577352] 0000:15:06.0: ttyS5 at I/O 0x8cf8 (irq = 132) is a 16550A
>> [    1.577590] 0000:15:06.0: ttyS6 at I/O 0x8ce8 (irq = 132) is a 16550A
>> [    1.577822] 0000:15:06.0: ttyS7 at I/O 0x8cd8 (irq = 132) is a 16550A
>> [    1.578054] 0000:15:06.0: ttyS0 at I/O 0x8cc8 (irq = 132) is a 16550A
>> [    1.578288] 0000:15:06.0: ttyS1 at I/O 0x8cb8 (irq = 132) is a 16550A
>> [    1.578522] 0000:15:06.0: ttyS2 at I/O 0x8ca0 (irq = 132) is a 16550A
>> Please help, how to configure the modem connected to the I / O card suit
>> (Tx)
> There may be any one of several things happening here which could cause
> the transmit to not work correctly.  I think you have not given us
> enough information for anyone to know for sure which problem you have.
>
> It would help if you could tell us:
>
> (1) When you try to TX, does your radio actually transmit at all, or
>      does it stay in RX?
>
> (2) If it transmits something - does it "sound like" a normal packet
>      transmission, if you listen on another radio?  Is it a single
>      tone?  Is it silence?
>
> (3) What options are you specifying when you load the baycom_ser-fdx
>      driver?
>
> I can make several suggestions about things which might be wrong.
>
> The documentation for the baycom_ser-fdx driver says that you
> should use the "setserial" command to tell the standard serial driver
> not to try to control the ports that you are trying to use with the
> baycom_ser-fdx driver.  It is not allowed to have two drivers
> trying to "own" the same I/O ports.
>
> Before you load the baycom_ser-fdx driver with "insmod" or
> "modprobe" you should use commands like
>
>     setserial /dev/ttyS0 uart none
>
> for the two ports you are going to use with baycom_ser-fdx.
>
> It is possible that your system is not transmitting, because
> the baycom_ser-fdx driver "thinks" that the radio is always
> receiving packets.  This could happen if you are using the
> "hardware carrier detect" configuration in this driver, and
> if your serial port UART is reporting that DCD is "on" for
> some reason.  If you use "hardware carrier detect" you should
> operate your radio with the squelch "closed" (silent when no
> signal is being received).  You can try operating with the
> squelch open, and with the baycom_ser-fdx configured for
> "software carrier detect".
>
> Another possibility is that the PCI serial card you are using,
> is not physically able to drive a Baycom serial modem properly.
> The Baycom modem and driver were designed to work with a "real"
> 8250, 16450, or 16550A UART and with an RS-232 electrical
> interface.  Some PCI serial cards do not accurately emulate
> these UARTS, and many of them do not have true RS-232
> electrical interfaces but only a lower-voltage version.
>
> There are several reasons why you might be having problems:
>
> -  The serial card must drive the TXD line to a "0" state
>     (high voltage) and must provide enough current on the TXD
>     pin to operate the Baycom modem.  It is possible that your
>     card's TXD line cannot provide enough current (or has too
>     low a voltage) for TX operation.
>
> -  The serial card RTS pin is used to drive the PTT signal to
>     the radio.  It is possible that RTS is not driving strongly
>     enough (too little voltage or current) to operate PTT.
>
> -  The baycom_ser-fdx driver actually transmits the HDLC
>     data by toggling the serial card's DTR pin on and off
>     rapidly.  It is possible that your PCI card's UART is
>     not toggling DTR on and off rapidly enough, and that this
>     is corrupting the HDLC data.
>
> You may need to look at the electrical signals between the
> serial port and the Baycom modem with an oscilloscope, to
> see if the DTR and RTS and TXD pins are being driven
> properly by your PCI serial card.
>
>
>
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Don't forget to measure the supply rail on the Baycom modem. I well 
recall one computer with insufficient RS232 capacity, resulting in the 
modem seeing 3.5V.  Baycom modems do peculiar things with only 3.5V <grin>

Not the issue here but I mention it as a warning to be vigilant; I had a 
25 to 9 pin adaptor which, unbeknown to me initially, had only THREE 
internal connections.

Ray vk2tv