8. ESD Analog Inputs for HIPPS
(almost certainly, ESD = Emergency ShutDown)
Input&Output Processing for HIPPS:
Process input
The inputs that are used to by the ESD (not clear whether they are discrete or analog)
Input Scaling
All field instruments are electrical devices that send an electrical signal to the controller. The controller considers these 'analog inputs'. The configuration of the controller converts the electrical signal to a man-recognizable scale with units, because programmers/operators/engineers don't know what the electrical 3.92mA value means, they need to know that 3.92mA represents 2.34 bar pressure. So the scale of electrical signal, typically 4-20mA or 1-5 volts, will be converted to a scale like 0-5bar pressure; 0-200°C, 0-1,000 liters/minute flow rate, whatever. Typically a linear, proportional conversion, but can require look-up tables or math conversions.
Control Set-point
The target value for the process. It's where you 'set' your thermostat.
Control Output
An output from the controller.
For on-off control output, a state of ON or ON.
Your home furnace is either on or off. The thermostat (controller) tells it to go ON if it's too cold; OFF if the room temperature is adequate.
For modulating control, an output signal runs from 0-100%, driving something like a valve, which closes at 0% and opens fully at 100%.