I have multiple read and write serial ports in series, but whenever I write to one, another one reads it.

[johnsold]

If the instrument is brand new, that is all the more reason to do it right. Over the lifetime of the instrument many changes will probably be made and any little bugs left behind in the early stages because "it works well enough for now" may become major disruptions later.

The real key to serial communication is to have a robust and well documented communication protocol. The only thing standardized about RS-232 is the voltages and the framing. A well designed communication protocol can run very reliably without the kinds of errors you are seeing and without the need for delays.

Do you have a communications protocol document?

Lynn

[billko]

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@johnsold wrote:

If the instrument is brand new, that is all the more reason to do it right. Over the lifetime of the instrument many changes will probably be made and any little bugs left behind in the early stages because "it works well enough for now" may become major disruptions later.

The real key to serial communication is to have a robust and well documented communication protocol. The only thing standardized about RS-232 is the voltages and the framing. A well designed communication protocol can run very reliably without the kinds of errors you are seeing and without the need for delays.

Do you have a communications protocol document?

Lynn

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I hadn't considered that this is a brand new instrument.  You're right - this may be the ONLY chance to get it right and not doing so now will only lead to heartache down the road.

[Dennis_Knutson]

Yes, imagine the frustration if a problem arises when an actual experiment is going to be run.