Implicit I/O messaging

[SOWEGATS]

Hi BobO!!

Please see my post above, from yesterday.

Many Thanks and God Bless!!

SOWEGATS

I've been out this entire week with COVID. I'll see if I can get someone else to answer your questions.

DUDE!!  Sorry to hear that!  Hope you get better soon.  I'll add you to my prayer list!

Thanks and God Bless!

SOWEGATS

[Greg]

Which command uses less network bandwith when reading/writing data to the input/output assemblies: Publish & Subscribe or Copy?

Well, I assume you are speaking of the instructions, PUBLISH/SUBSCRIBE and COPY, which you are using to as pre- or post-processing of your T>O and O>T data. The EtherNet/IP comms happen during the Comm Cycle of the PLC scan, while those instructions happen during the Execute Program portion of the PLC scan. So, in that respect, those instructions do not have a "bandwidth" per se. But, technically, PUBLISH & SUBSCRIBE are memory operations and native instructions to the BRX CPU, and as such, happen extremely fast. The COPY "instruction" is not a native instruction, but more of a macro. So, depending on what you are having the COPY instruction do, it could easily take more execution time (which still won't be much of anything) than the PUBLISH or SUBSCRIBE instructions.

4) Only real problem I have is that the Enable bit for the motor is dropping out randomly, but re-establishing so quickly that I cannot catch with the PLC (faster than the BRX Scan Time, but slow enough to shutdown the motor).  Is there a network buffer that is causing this?  Or a network speed (200 packets/sec) - vs - PLC Scan Time issue?

It would seem to me if "the Enable bit for the motor is dropping out randomly," that it is actually being written OFF randomly. But in your Adapter settings, what are your RPI values VS your PLC's scan time? Also, the EtherNet/IP Scanner Monitor might show something telling. Have you looked at that? (see Debug --> EtherNet/IP Scanner Monitor)

[Controls Guy]

I've been out this entire week with COVID. I'll see if I can get someone else to answer your questions.

Oh no!   Hope it's not hitting too hard and you're on the mend already.

[Controls Guy]

The bigger brother to BRX I referenced will be rack based. The 205 backplane isn't going away anytime soon, but we'd like to have a higher performance and more modern alternative.

Cool!  By bigger I assume some combination of taller/deeper (maybe 405/SLC-ish size?), higher max point count per module, bigger memory, maybe faster CPU (although the current one is pretty fast already)?

[BobO]

Oh no!   Hope it's not hitting too hard and you're on the mend already.

Wasn't fun. Should be back to work Monday, but now wife has it. Dandy.

[BobO]

Cool!  By bigger I assume some combination of taller/deeper (maybe 405/SLC-ish size?), higher max point count per module, bigger memory, maybe faster CPU (although the current one is pretty fast already)?

Yes on the form factor.

DM2 CPU will be a dramatic upgrade in some ways, while maintaining what has made us good.

[SOWEGATS]

Hi BobO and Greg,

I changed my RPI from 10ms (200pkts/sec) to 100ms (20pkts/sec) and my dropped Enable bit problem went away.  My simulation has been running now for about 5 hrs without a hiccup.  That's about 6100 total cycles = about 1500 cases (PNP Case Packing Y-Z Robot).  My PLC Scan Times are about 452microsec Min, 470microsec Avg and 2.5ms Max.

Still not sure what the problem actually was, but seems like, maybe, I was overloading the network?  Any thoughts?

Take Care and God Bless!

SOWEGATS

[BobO]

Hi BobO and Greg,

I changed my RPI from 10ms (200pkts/sec) to 100ms (20pkts/sec) and my dropped Enable bit problem went away.  My simulation has been running now for about 5 hrs without a hiccup.  That's about 6100 total cycles = about 1500 cases (PNP Case Packing Y-Z Robot).  My PLC Scan Times are about 452microsec Min, 470microsec Avg and 2.5ms Max.

Still not sure what the problem actually was, but seems like, maybe, I was overloading the network?  Any thoughts?

Take Care and God Bless!

SOWEGATS

There are a lot of moving parts. When you shorten the RPI, you are also shortening the timeout, which is a multiple of the RPI. Of course you are also increasing the amount of traffic, but the PLC can handle that easily. It's really hard to know without a Wireshark network trace.

[unsyndicated]

Forgive my ignorance, but how does one go about assigning addresses if the EDS file doesn't populate the configuration data field?  It does populate the messages field where i'm able to select listen/input etc. 

I'm attempting to control a IAI robo cylinder with a pcon/cb controller via Implicit messaging.  Simple three position movement.

Regards

[MAEdwards]

Create or specify a data block in the 'Local Addr:' field of the T->O (Input) section that will be used to store the data coming from the PCON/CB controller (Target-to-Originator).

Create or specify a data block in the 'Local Addr:' field of the O->T (Output) section that will be used to transmit data to the PCON/CB controller (Originator-to-Target).

If the EDS file for the PCON/CB controller does not include Configuration Data, then configuration of the PCON/CB controller is not performed through the establishment of the IO messaging connection.

I have attached an image to help illustrate the setup.

[unsyndicated]

This is all a little above me, but i'm getting there. 

Can i simply use copy and move to get the data back and forth?

[MAEdwards]

One approach could be...

• Find the structures for both the T->O (Input) Data and O->T (Output) Data of the target device in the vendor documentation.
• Create a User Data Type (UDT) that includes the structure elements of the T->O (Input) Data and O->T (Output) Data.
• Create an Instance of this User Data Type (UDT), either as a Heap Item or a Memory Block.
• Use the COPY instructions to move the data in to and out of the array elements and UDT structure members.

[unsyndicated]

I apologize for not responding sooner, but i shelved this project for a while.

I came back to it I feel I have a decent grasp on the udt/heap items.  My controller is showing that communication between it and the plc isn't established.  I'm able to query adapters and find it without any issue. 

My ip addresses and gateways all match up, is there any other settings i should be looking for, I've been going over this for a few days trying to get it on my own but to no avail.