the 4017 has an enable pin but that means using 3 outputs to drive it.
is the '138 guaranteed glitch free?
yeah, if your interface parts support that, it seems the best way to go.
-- This email has not been checked by half-arsed antivirus software
Never had a problem using a standard MUX like the 138. If I need a park position I leave one output free and set the Mux to that.
Cheers
I've been looking at other PLC controller offerings, and thus far the comes out ahead; it does a lot of what we need in a package with a good price. Alternatives I've found either cost far more or require lots of integration. (I've just been pointed at the Siemens Logo line and am looking into it now.)
The Digital Logger has other things we don't need but we can ignore them. It does not have one important item, wired Ethernet.
I'm pondering how that could be added outboard. What we need is really a terminal server: serial from the PLC on the one side, and TCP/IP on the other. You can buy such in a shiny box for say $100 or less for boxless The latter requires making a PCB, worrying about power, etc. Any alternatives you're aware of?
-- A host is a host from coast to coast.................wb8foz@nrk.com & no one will talk to a host that's close.......................... Unless the host (that isn't close).........................pob 1433 is busy, hung or dead....................................20915-1433
Why don't you just get a controller that includes Ethernet to start with?
I haven't seen where you explain why you are only looking at PLC controllers rather than generic CPU boards. From how you have explained your needs so far, there is nothing in a PLC that you will use that is different from a CPU board. From what I can see, you would do well with a Raspberry Pi or a Beagle Bone Black type board. Ethernet included and tons of support (metric tons even).
So what do you get with a PLC that you don't get with one of the *many* CPU boards?
-- Rick C
The controllers we have seen are 6-12X the price of this approach.
This controller has value-added in integration, packaging, input protection and such. They have done things we will not have to ourselves.
We looked at Beagles but want to avoid the issues with supporting a Linux device. (& that would be far more overkill.)
I've not found an Arduino case/touchscreen/AD/input protection/ etc that we can plug in and fly with. Suggestions?
-- A host is a host from coast to coast.................wb8foz@nrk.com & no one will talk to a host that's close.......................... Unless the host (that isn't close).........................pob 1433 is busy, hung or dead....................................20915-1433
The first problem is I don't know what your requirements are. The second problem is I usually get paid for this sort of thing. When you say things like you "want to avoid the issues with supporting a Linux device", that makes me think there are many more issues to deal with that you haven't explained. The term "input protection" is entirely vague. There can potentially be a huge list of such requirements that you need to detail before anyone can try to find hardware for you.
-- Rick C
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