CLX Redundancy/Scantime/ControlNet

RSL said:
My problem lies in the redundant pair. I have 2 issues.

Scantime causing missed inputs on counters. Scantime is about 425-460ms
Controlnet unscheduled bandwidth insufficient to allow for expansion or online editing in a timely fashion.

I believe both of those things can be affected, positively or negatively, by adjusting the overhead time slice in the CPU.

Additionally, you said you were using for-next loops. If there is ANY way you can eliminate them, do it. They add decades of scan time to a program. If you're indexing through a data table, as you said, you can sometimes get away with accessing one or two data members per scan. Use an incrementing counter to take you through the table, and trigger a bit when you're done. I've done this little trick a number of times to create alarm logs, and other data tables for display.

AK
 

Similar Topics

Hello, I just want to be sure if it is possible or not to add hardware to a ControlLogix redundancy system without stopping the PLC. Thanks
Replies
1
Views
2,051
Hello all, Requesting help from all CLX guys. This is my first prj with redundancy on L61. Though I handled CLX for many projetcs , Till now I...
Replies
8
Views
5,651
I will be likely designing a CLX redundant system sometime soon and I have two questions: 1. The process is a water treatment plant that does...
Replies
8
Views
4,550
K
I have a CLX redundant system that contols some critical systems at our facility. It is dificult to operate these systems in "local control"...
Replies
6
Views
7,249
Controller: 1756-L84E v.35 Prosoft MVI56E-MNETC for ModbusTCP/IP I'm having an issue with some of my write commands. The write command that...
Replies
0
Views
200
Back
Top Bottom