The following information is provided in response to problems
choosing or making serial cables to interface radios with WL.
I sympathize with anyone trying to figure out the so called "RS-232-C"
standard. Perhaps I can explain a few points about it.
1.) First, ignore all the talk about what sex (male/female) and
number of pins on each end of the cable per any manual. Simply
look on the rear of your computer to see what type of serial
(or COM) port connector it has. Likely it will be a MALE 9-pin
or 25-pin ON THE COMPUTER. Then look on the back of the radio
to see what type of interface connector it has - - It will again
likely be either a 9-pin or 25-pin but it may be either sex.
NOW - GO BUY A CABLE THAT PHYSICALLY FITS BETWEEN THE TWO CONNECTORS
THAT IS WELL SHIELDED AND ONLY LONG ENOUGH TO COMFORTABLY FIT.
2.) Second - There are still several traps to fall into about how
the cable is wired. A little history will help...
A. Early PCs used external modems which were hooked up
with 'straight-through' or so called 'modem' cables. By this I
mean pin 1 on one end went to pin 1 on the opposite end and this
continued for all 25 (or 9) pins - - In other words, there were
no 'crossed' wires where a wire went to DIFFERENT pin numbers
on each end.
B. A second type of serial cable was needed to connect
two PCs together because the transmit data being sent from one
needed to be connected to the receive data pin on the other.
Hence a 'null-modem' cable was created that cross-connected
the receive and transmit data (pin numbers 2 and 3 on a 25-pin
plug by the way) and also cross-connected some handshaking
lines so each computer could pause the other if the data was
flowing faster than it could handle. These 'null-modem' cables
can be made by using a small adapter (just ONE) on either end
of a standard MODEM cable. In that case the adapter does the
wire crossing for you.
C. There are also dozens of 'special' cables that are
designed to interface specific equipment using RS-232-C which
do NOT conform to either of the above configurations. Often
serial printer cables and other business hardware use these
sometimes even with custom software to make them work!
SO HOW SHOULD YOUR CABLE BE WIRED? 'MODEM' OR 'NULL-MODEM'??
I SUGGEST YOU BUY A STRAIGHT THROUGH MODEM CABLE AND A NULL-MODEM
ADAPTER. INSTALL JUST THE CABLE FIRST AND SEE IF IT WILL WORK.
IF IT DOESN'T, THEN PUT THE NULL MODEM ADAPTER ON EITHER END OF
IT AND TRY AGAIN.
One thing they did get right is that the RS-232-C (now EIA-232)
standard allows shorting pins to each other and no damage will
occur to the hardware. This allows trying a cable that may be
wrong without fear of 'blowing' the port in the equipment.
By the way - THE ABOVE IS NOT TRUE FOR PARALLEL PRINTER PORTS!
3.) Once you have the right cable, you should get some response
out of the rig. Be sure to power on the radio BEFORE running
Write Log. Also be SURE that the SETUP PORTS menu in Write Log
is set for ONLY ONE FUNCTION for each of your serial/COM ports.
That is, a single port may be used for rig control, sending CW,
doing packet or antenna rotor control - BUT NO TWO OR MORE OF
ANY OF THESE! If you set the software to the wrong driver
(different rig than the one you have) or the communication
parameters (baud rate, number of data bits, number of stop bits
handshaking mode or parity) are wrong - The radio will likely
do SOMETHING but obviously it won't work correctly.
4.) Finally, the design architecture of the PC causes some
strange results when you attempt to use more than two COM
ports because of the sharing of hardware interrupts. Without
getting too technical, be aware that often devices that use
COM 1 and COM 3 may not work simultaneously because they share
IRQ 4. Likewise, COM 2 and COM 4 devices share IRQ 3 and may
not work simultaneously. To check this out, get all your
Write Log devices working ONE AT A TIME. Once you achieve
that, then try to use them simultaneously.
Many times an internal modem that is used to access the
internet won't function properly with Write Log running.
In fact on my machine, I get a "SERVER FUNCTION FAILED"
error message from Write Log if I go online while my radio
is interfaced. The cure is to assign a different interrupt
(IRQ) to COM 3 and COM 4 but this requires both hardware and
software that will allow you to do that. Often some devices
will work OK because they don't generate interrupts but I
don't know how to tell in advance without simply trying it.
- - -
I hope this long rambling message makes some sense to you
Doug. By the way, my all capital letters above isn't meant
to be yelling - - I thought those statements would be the
specific information you need to correct your problem.
Write Log isn't 'bug free' but it works superbly and is very
flexible and powerful. I've used it for over 7 years now
with good results.
73,
Bob Helms, AF5Z
af5z@inetport.com
--
WWW: http://www.writelog.com/
Submissions: writelog@contesting.com
Administrative requests: writelog-REQUEST@contesting.com
Problems: owner-writelog@contesting.com
|