Each DeviceNet S-Series interface card supports up to 61 nodes but the card has internal memory of 10Kbytes only.
How to calculate total parameters polling limits per segment if the segment is fully loaded?
Is there any spreadsheet / formula to calculate segment communication loading and performance prediction at various baud rates and various parameters at various polling rates?
Thanks
Kishor
Kishor, I saw an email back on this I wanted to pass along:
We’ve never seen anything hit a limit before. Number one, it’s very unusual to actually load a segment up to 61 nodes. Beyond that, typical I/O byte sizes are 8 bytes IN / 8 bytes OUT, so even if you had 16 bytes for each of 61 nodes, that is still less than 1K byte.
I'm not sure how much internal memory is available for device data. My guess is probably not the whole 10K.
The most likely thing you’re gonna see with “loading” is just how long does it take to poll all 61 devices and also communicate some of the diagnostics. The highest baud rate is 500 K bits per second. If it took 5 ms per node (which is probably way slower than reality), that would be 300+ ms per scan. The scan rate would be more or less proportional to the number of devices.
I'll pass along anything else I see.