HT1000 / MTSX Ribless Cable Construction

compuman81 · Post by **compuman81** » Thu Feb 23, 2006 1:05 am

As you can see, i'm building a ribless cable for a quick and dirty programming job, but I don't know where to get Bar Busy, the not busy. I suppose I could just tie the RTS/CTS pins from the Serial port into a voltage inverter similiar to that used on the sandy ganz rib to get the -5 Volts and then run that signal to the contact on the radio along with BUS+ and GND, can anyone verify my idea or make a suggestion?

kcbooboo · Post by **kcbooboo** » Thu Feb 23, 2006 5:19 am

There are schematics of the Motorola RIB elsewhere on BatLabs.

Follow the circuit for BUSY. It needs level-shifting and possibly inversion as well. See where that goes, and duplicate it on your own version.

Many radios use the BUSY line. Many radios do not. Anything you build yourself must exactly mimic the Motorola RIB in function.

Bob M.

Will · Post by **Will** » Thu Feb 23, 2006 1:56 pm

Also note the resistor values that were changed to match the RS232 standard, and allow the finikey computers and RIB to opperate correctly.

The _BUSY line has the inverters and has to lop back to the serial port. THe RSS uses this in a couple of ways, so the levels and timming have to be correct.

compuman81 · Post by **compuman81** » Thu Feb 23, 2006 4:47 pm

the schematic that I have shows a 4.7 K off the serial port from computer into a diiode and another 20k resistor tied to ground, from there, the signal goes to the base of a npn transistor and the emitter signals the Not busy on the radio. This should work in conjunction with the 232 level conversion circuit which is separate, correct?

Will · Post by **Will** » Thu Feb 23, 2006 11:34 pm

Hard to tell without looking at your 'roadmap' ( schematic).