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Is it possible to perform an output from a SFC to a serial card/landing module reference to open and close a solenoid in an external injection system?

I'm considering using an SFC to generate an output every time calculated injection period, through a serial card/link to open a pump solenoid in a Honeywell Enraf Fusion 4 additive injection system.  The output, depending on the tonnage required, would be approximately every 5 secs to add the appropriate amount of additive.  The SFC would be started by the operator who would enter the required tonnage and approximate loading rate to calculate the injection time period.

I'm wondering if this is actually possible?

We've been advised that using a DO charm is not desirable and that a relay baseplate would be required.  These however have a lifespan of 1million outputs giving short operation due to the large number of outputs required each load.

Can anyone advise please or suggest another solution?

Thanks.

1 Reply

  • It sounds like two questions here. Regarding the control logic, an SFC can write to a serial card DST via a landing module, just as it would to any type of output. Are you having a specific situation that you feel would prohibits this?
    Regarding the cycle life span of a DO charm versus a serial connection, I can't say, but if high availability is a concern, a redundant set of IO would work to your advantage, so that even if you weren't tracking cycle count of the component, logic to distribute or switch over to the other output channel would buy your instrumentation techs time to replace the failed compenent provided you have some sort of device alarm set up.