[Premium-Rx] Racal A6A1 Board Setup Help Needed

[Claus Hanke]

Hi Guy,
to configure the serial interface you can use the GM-3 manual, the jumpers have the
same name and function in both versions (see A6A1 sheet 1 of 2) in case we have
the same manuals. You need to correctly jumper the interface type - 422 or 232
(see Table II and IV). The next thing is that you need to configure the Remote Connector
for the speed (TableI,  III) and receiver's address (Table I). If you leave pin "U" open
then there is no Parity. Since you only can address 99 receivers, I don't know if you can
leave all address pins open. I'm not quite sure anymore if it's 8 or 7 bits but I would start
with 8 bits, no parity and 1 stop bit. Maybe not use the highest baud rate. I also would
try it first out with a normal terminal program before using the one you have.
Chapter 3.3.5.4 is explaining the commands - $99S2<CR,return> if first sent makes the receiver
with the address 99  active for all subsequent commands until a new address is sent, otherwise
all commands must be started with the $address command.
To configure the address, the easiest would be to use 77 and ground pin "N" and "T", BCD coding
for the address. Since the receiver doesn't provide CTS, RTS signals, you might need to
short the pins on the PC. Pin "Z" to ground selects 9600 baud. If you get it to run you may try
19200. The GM manual also says that the link LK1 on the A6A2 board need to be removed.
Because I don't have my receiver anymore I can't check it out, but as far as I remember even the
remote board is installed, I still could switch between remote and manual and the receiver showed
normal data on the displays.
Regards Claus

Guy Atkins wrote:

> Hi Claus,
>
> Thanks for taking the time to look up this information. I knew that my
> receiver has the GM CPU board with the 3 EPROMs, and I just verified that
> the remote board is also a GM model with the IM6402 UART.
>
> So, I have the correct combination of boards, but unfortunately my manuals
> cover the GM-3 version.
>
> Could you tell me what your GM manual says is the normal serial protocol? Is
> it the common 8-N-1, or maybe "1 start bit, 7 data bits, a parity bit, and 2
> stop bits" such as the GM-3 manual states?
>
> Thank you,
>
> Guy
>
> -----Original Message-----
> From: Claus Hanke [mailto:claushanke at yahoo.com]
> Sent: Sunday, February 22, 2004 9:28 PM
> To: Guy Atkins
> Cc: Premium-Rx
> Subject: Re: [Premium-Rx] Racal A6A1 Board Setup Help Needed
>
> Hi Guy,
> I checked both manuals, GM and GM-3, and it is not possible to mix the
> boards.
> So, if you have a remote for the GM-3 (UART 8251) you cannot use it with the
> GM CPU board (3 EPROMs and 3850 CPU). The pining between the boards
>  used by the GM and GM-3 versions are different. The GM-3 CPU is a Z80
> (1 EPROM). The UART on the GM remote board is a IM6402 or compatible.
> That would explain that the receiver is not working anymore. Pin 2 - GM is
> the
> RESET (active low) and MI (active low) for GM-3. I'm just guessing, but
> maybe
> the CPU is always in RESET mode.
> Anyhow the two versions are not compatible, so check what versions you have.
> Hope that helps.
> Claus
>
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