Hello,
We looking into using EIOC cards to communicate with a bunch of PLCs. we have approximately 60 PLCs and each containing about 4 Control Logix tags of array type. approximate array sizes are 20, 20, 50, 50. I looked at the limitation table provided in the BOL and the number we have are less than the requirement for Logical Devices, Physical Devices, Total DSTs and Total EIOC signal tags. Can I have all of these PLCs into one redundant EIOCs or should I need two EIOCs? The Table doesn't provide the how fast EIOC can read the values. or if it is going to cause any data stagnation.
Thank you in advance for any help
Arunan S.
Arunan,
The EIOC Product Data Sheet lists the overall capacity of the device. Based on your description of the system, one EIOC (or redundant pair) should be sufficient."The EIOC provides direct access for up to 256 physical devices. For each of the 256 Physical Devices (PDTs), the EIOC data hierarchy supports up to 256 Logical Devices (LDTs). These Logical Devices can supports up to 100 data values each.""Each EIOC is capable of handling a huge amount of Data in up to 2000 Control Modules. The data can be collected from 256 physical devices that have up to 256 logical devices and a total of 32,000 data values."The rate at which the EIOC can read (poll) varies by protocol, number of physical devices, and number of signals. At the maximum of 256 physical devices and 32000 data values, there should be no noticeable delay. Since your system has far fewer than 256 physical devices and far fewer than 32000 data values, I would expect polling times at or below 100ms.Best regards,Ben
Also keep in mind that these aren't the only limitations that you need to worry about. There are also function block limits so depending on how you will be using the data could be a limiting factor as well.
Here are the block limits for the EIOC:
In reply to Ben Bishop:
In reply to Matt Stoner: