Time heals all wounds
explain these terms (scaled set point, controller gain, feed forward bias)
Yes, and it takes time to become familiar with, let alone proficient with all the ins and outs of this field. Pardon the pun! But the definitions are as follows:
Scaled set point - Most often any value that is scaled is being converted from just raw data to some meaningful engineering unit. I.E. Percent, PSI, Degrees, etc. Scaling always involves moving data from one value to another to make it more useful to all who encounter it.
Controller gain: Gain is just like it sounds, if you consider the term. In a PID or other control loop it is a value that addresses how responsive you want your system to be to the magnitude of the error between the setpoint and the process variable you are trying to control. In other words, how much corrective action do you want in response to the presence of error. To high a gain value will make the loop unstable and it will oscillate and if the gain is to low, the loop will never come into control and will act unresponsively.
Feedforward bias is an attempt to anticipate what the upset or disturbance in a control loop will be. Much like the anticipation built into your home thermostat that keeps your home from experiencing uncomfortable temp swings. Adding this bias or offset to the output Control Variable (CV) will in some cases make a control loop more stable.
SCL and SCP are almost identical instructions with minor exceptions. They both produce a linear output between an input value and scaled values. In other words, they are both scaling instructions but depending on which processor you have and also your own understanding of what they do, you can use either. They allow you to take a raw input or output value and scale it from the plc's decimal value to engineering units or vise versa.
Don't be too hard on yourself, if any or all of this makes little sense. There are other ways of describing these terms and you will find the ones that suit you best. I just hope this helps a little.
