Override control with fanout

Hello, At least one of the commonest DCS systems doesn't 'officially' support override control with fanout. Has anyone got any suggestions on how
to handle this configuration?
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bruce varley wrote:

Hi Bruce,
I know that you were involved in petro-chemical process systems so have already begun thinking that you have some plant that you need to provide these overrides for. However, it would help us all if you elucidated slightly more what it is you are intending to achieve.
In one of my own designs the control aspects would happen quite autonomously but the central operator was able to override the controlled operations in order to allow exceptional operations to take place. This was, however, for a rail based system. Your situiation may be different.
So, pray, a little more clue to what you are needing.
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Hi Paul, Can't share any more, unfortunately. The terminology in my OP will have to suffice. This is specifically a 'platform limitation' issue rather than a control probem. Regards

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Some possibilities come to mind.
(1) Configure the secondaries to pull in their SP. (2) Use an intermediate automan "station" to implement the fan out. (3) There may be a fanout block (c.f. Honeywell Experion PKS).
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Hi there,
Can I ask what may be a dumb question. What is Fan Out? We use a lot of override control in our plant, but I've never heard the term before.
Thanks. Curtis
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Curtis, Refers to the situation where a controller output drives setpoints of multiple secondaries in parallel. In this case, each output path is subject to overriding by a local constraint controller.

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