Speed control

[RobertL 1]

Hi everyone, I'm working on a personal project and I need some help. The project consist of controling the speed of two DC motors using a MicroLogix 1000, and a C-More HMI, but I don't know which instructions to use. I'm using RSLogix V.8, and RSLinx classic. Any help would be greatly appreciated.

[panic mode 246]

what is the type of drives you use to power your DC motors?

[RobertL 1]

I'm using a KBIC-120, 90 VDC speed control.

[panic mode 246]

then you need to google that which will bring you to: http://www.kbelectronics.com/manuals/kbic_manual.pdf sections 9.3 and 9.4 talk about speed control using external reference 0-7V. of course you need to follow instructions on wiring but as PLC is concerned, you just need analog output (0-10V and limit it in software to 0-7V). but micrologix 1000 is not expandable and if i recall only one model has analog IO (of which only one was output i think, the other four are inputs). writing to analog output is simple, you just use MOV instruction for example. normally analog output values would be in raw counts so for example 0-32767 would represent range 0-10V, in which case 7V would be about 22937 counts. if your program uses 0-100% as speed value, you can just multiply that by 229.37 and write to analog out. .

[RobertL 1]

Thanks a lot.