Control Logix Scaling

Im having trouble scaling analog on control logix? Can someone explain how to scale analog on control logix analog module 1756-IF4FXOF2F?

Hi

I have not used that card but on any control cards I have used the scaling can be done in the properties of the card.what trouble are you having?

Donnchadh

Try using the SCL instruction.

The type of analog card you are using doesn't really make a difference, it's all how you set up the SCL.

You can (and I prefer to) scale to engineering units on the module itself.

Double-click the module in the IO Configuration, and in the dialog that pops-up, choose the "Input Configuration" tab.

Choose the channel you want to configure, and set the input type (top right).

then on the left set the 4 parameters - input signal min/max, and engineering units min/max.

repeat for all input channels, then do the same for the 2 output channels, but here you will be specifying the min/max output for min/max engineering units in the controller.

it really is that simple. the configuration is downloaded to the module, and everything you see in the tag database is in the engineering units you chose.

The 1756 analog cards can also do your LL, L, H, and HH process variable alarms too, complete with alarm deadband control to stop "alarm jitter", and there is also a "rate of change" alarm you can use to determine if the analog signal has changed more rapidly than the process would allow, indicating a measurement fault, or a catastrophic failure on the plant.

Outputs can be configured to have a "ramp to new value", and can be configured to go to a "failsafe" value if a fault is detected, or if the processor loses comms to the module.

All this functionality without having to write a single piece of code in the controller....