scrachdat said:
I have purchased from kelly, an SM-4a to DB9 converter.
then from this I have db9 to usb prolific chip set serial cable.
also I have tested the pins on the sm4a to db9 adapter and I don't have anything close to 15V only 5V or 4.3V
Okay - so you have a KBS-X controller with the in-line pins not the plain KBS with the DB-9, correct?
My Bad - I thought you had the KBS type with the built-in DB-9.
Pulling down the KBS-X manual, I see this:
So - it looks like you have the proper adapter to get to DB-9/RS-232. But the voltages on the DB-9 make no sense for RS-232.
I think this is what you have (you really need to post links so we know exactly what you have...)
http://kellycontroller.com/sm-4a-to-db9rs232-converter-p-1403.html
The nature of the controller connector is such that you need this adapter.
Which is meant to mate with this:
http://kellycontroller.com/pc-cable-and-usb-to-rs232-and-sm-4a-to-db9rs232-converter-p-316.html
You got a different one and that may be the issue... (TX/RX cross-over? Real RS-232?)
Three things to check:
(1)
From the manual you should see the +/- voltages on the outer pins of the in-line SM-p connector. Try pulling off the adapter and just measure the voltage on the outer pins against Gnd (any of the RTN pins - 6, 20, 21) (careful not to short things out!). Oddly, there is no ground reference on that in-line pin set - the manual is pretty vague as to what is to be found there.
(2)
Check the voltages on pins 2 and 3 against GND pin 5 for the SM-a to RS-232 adapter. You may have done this above, but this is just to be sure that you measure against the signal ground on the connector.
(3)
Do the same voltage checks as (2) on the DB9/RS-232 to USB adapter on your laptop.
The important results are from (2) and (3) - with luck, the voltages will match up and these two connectors can safety talk to one another. The test in (1) is sort of a research project, so don't lose any sleep if you don't want to fiddle around with it.
All that aside, the Prolific chip set is annoyingly finicky and there are many trashy drivers that just plain don't work. ES is filled with posts about folks having issues. I personally have four sets of drivers and only one works on my laptop. Not saying that's your problem, but there's a history there...