NOC 401 - synchronous or asynchronous

David-B · ‎2024-06-20

I have a bunch of remote IO communicating over Ethernet/IP thru a BMXNOC401.2 card. Does anyone know if that I/O is scanned such that its synchronous or asynchronous to the PLC logic?

Bosswaffle · ‎2024-06-23

I would think that almost all comms are asynchronous. I mainly say this because the READ_VAR FB explicitly states that it requires multiple scan cycles for execution. Even the default repetitive rate of the IO scanner is in the hundreds of millisecond range.

David-B · ‎2024-06-25

I might be doing something wrong. I did not think its necessary to use a READ_VAR_FB. The I/O is coming into a BMXNOC401.2 card and the devices are Itoh Denki IB-E03 cards. When I added them to the device list for the 401 card it assigned memory addresses and shows a Scan Rate of 30ms.

I have a meeting with Schneider Electric Tech support this coming Thursday. I'll run my configuration by them.

Bosswaffle · ‎2024-06-26

You're correct that you don't need to use the READ_VAR blcoks, since you are using the IO scanner built into the BMXNOC401.

Pleas share the response for tech supoport when you can, I'd also like a difinitive answer to where or not the IO scanning is synchronous or asynchronous.