PLC and HMI Network

[mmervenne]

I currently have a PLC Network with a FX2n PLC, a fx2n-8ad, a fx2n-4da and a mitsubishi e700 HMI. I want to split my current plc program into two and add another fx2n plc to run the second program. My question is should i also add a fx2n-8ad and a fx2n-4da or can i use my existing with two plc's. Speed is the main issue here which is why i am breaking up the program. Also how easy is it to have two plcs talk to the HMI. Any help is greatly appreciated. Thanks Mike

[tmu]

E700 supports dual driver, and cable btw E700 and FXPLC is CAB19 from PLC to E700RS422 -port. In 2nd PLC case (2 FX's to E700) you would need PLC<>E700RS232-cable. I am not sure what this cable is, but i would try with programming cable SC-00 or SC-09? Tmu

[Crossbow]

If you go to www.e-terminals.com and choose anywhere outside North America, you can go into the Info section and choose the cable guide. But the one you need here is the CAB5. I would recommend that you put an RS232 board on one of the PLCs and connect it to the E700 RS232 port with the CAB5 (which is the programming cable for the E700) and leave the CAB19 and existing PLC on the RS422 port. You can then set up an automatic data exchange between the two CPUs in the E700. If you're concerned that serial won't be fast enough, you will need to spend some money and get an FX2N-16CCL-M CC-Link master for one PLC and an FX2N-32CCL for the other. That way the two PLCs can talk to each other over a faster network. The comm board RS232 will set you back less than $100, while the CC-Link solution will be more around $600. Is this a huge program? Why would you want to split it into 2 PLCs? Another option would be to replace the FX2N with the new FX3U, which is a bunch faster. You can continue to use the FX2N extensions and analog modules on the FX3U.

[mmervenne]

Thanks for the info guys, alot of good info. Splitting the program is something that the customer wants to do. One of my questions is should i add another FX2N-4DA and FX2N-8AD, or can both plc's use these. I am new to mitsubishi. Thanks for your help.

[mjrx]

Different communication schemes can add overhead to your programs as well, so you may net gain much in increased PLC speed, if that is what you are after.

[Crossbow]

Since you asked it again, I'll respond again.. There is no way to use the same extensions on two PLCs. But if you network the PLCs together, the data from those modules can be shared. As was just stated above, adding networks can add to the processing time of the PLC. I still say if speed is such a major issue, change out the FX2N for an FX3U. Either way, these are some of the fastest Micro PLCs out. If you need much more, you'll need to go up to a rack-based controller like the Q.

[panic mode]

what kind of speed you expect? what is the current scan time of your program (with both programs in same plc)?