--- In ts-7000%40yahoogroups.com, "Charles" <> wrote:
>
> Hi --
Hi, and Thank You Charlie...
>
> --- In ts-7000%40yahoogroups.com, "enrique_cesena" <enrique_cesena@> wrote:
> >
> > Hi, I'm using a TS 7300 Board to implements control system, the board must be connected to a device using 4-20mA Current Loop communication, is it possible to implements this communication using DIO in the TS7300, with the minimum external electronic interfacing.
> >
> > Any Ideas?
>
> Can you clarify what you mean? I see (3) different possibilities:
>
> * 4-20 mA analog input you want to read (TS7300 as process monitor)
> * 4-20 mA output, ie, setpoint, (TS7300 as process transmitter)
> * Current loop serial communication: like RS-232 but using current level to signal. Does anybody do that anymore? I haven't seen that for decades; last time was on a DataGeneral minicomputer.
>
Is the third option: current loop serial comm, and yes it's still used in some devices that need long distance comm and isolation protection (in this case is a dispenser machine), as you can see I'm not an expert in electronics.
> Really though, any one of these will be hard to do with DIO alone. RS-232 to current loop converters are (or were) available for the third option. Analog input will need an A/D converter, and analog output will a DAC (that you could drive with DIO).
There's available options but the most implements rs232 to current loop converters.
I'm trying to implement if not with DIO alone (sounds impossible to me) but with the minimal implementation of electronics. The question it can be: Is there any diagram or anybody knows how to implement a current loop serial communication using directly the TS DIO? it's ok if is necessary to use an external implementation of electronics (opto-isolator, amplifiers, resistors) including external power for the isolated side.
Kind of Regards
Enrique
>
> regards, ......... Charlie
>
> >
> > Thanks in Advance
> >
> > Enrique
> >
>