Created Date: May 11,2004

Created by: marksji

What two outputs will the master PLC be turning on/off on the slave? I 've found the ethernet comm cards to be very reliable (when used with AD switches) and fast as well, but fast enough to do direct process control I don't know.

We do something similar with our products, but our central PLC only sets the set-points and monitors the "slave " PLCs. All the process control logic is in the "slave " PLC for saftey reasons and should our comm fail an error is displayed on the central PLC.

Created Date: May 11,2004

Created by: Samu

I don't believe the 06's can control everything because there are central components that are common to all 50 machines.

Each time a machine loads it must also turn on the vacuum pump that is shared between 15 other machines, and only 1 machine can load at a time.

I think the 06's would fight over this resource. So it sounds like this is not a good concept??

The loading process is not fast, would be like this. The 205 would turn on vacuum pump and tell an output to turn on for 3 seconds on the 06, after this fired then a second 06 output would fire for 10 seconds.

I could also use the 06 to control the local outputs and timers, and just have the 205 send a "Go " signal to the 06 as it turns on the vacuum pumps.

thanks,

sam

Created Date: May 12,2004

Created by: Gerry

Sam,

This concept, that you last mentioned, makes sense:

"I could also use the 06 to control the local outputs and timers, and just have the 205 send a "Go " signal to the 06 as it turns on the vacuum pumps. "

I do this same thing with a line of pump testers that share a 50HZ M-G set. Each tester makes a request to a 205, when the M-G set is warmed up and ready the tester receives a "GO " signal. Each individual pump tester has its own logic for everything else.

The only difference is I only have six shared machines, not 50.

As long as you don't do critical timing type controls on the machines with the 06's using the 205 you should be fine. Use the 06 for all the time critical stuff.

Created Date: May 11,2004

Created by: Samu

We are replacing a material handling system for our molding machines. It is based on a single PLC controller and hardwired to/from each machine.

I am considering using an 06 on each machine (50 machines) and communicate via ethernet (or devicenet) back to a central PLC (205 or 405). The central PLC will read 1 input(needs material) and control 2 outputs on the 06 unit, plus turn on the central vacuum system to cause the loading.

Is the Ethernet communication fast enough and reliabe enough to do this in a manufacturing enviroment? Each machine will load ~3 minutes, and multiple machines will be requesting at the same time.

I realize this distributed system is overkill, however my ulterior motive is to also use the 06's to monitor my machine cycle times and run hours. Then communicate THAT info back the a PC via DDE to an access database.

Am I dreaming, or is this doable???

Any comments or recommendations would be appreciated. Let me know if you need more info.

(posted in comm and general topics)

Thanks,

Sam