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From time to time I upgrade a machine built in the 80's or 90's that was all 120V AC inputs. This is clearly a United States issue, but it's kind of a pain to stack a whole bunch of IO-DI8ACH modules.  It makes me add an EX-RC1 module which complicates a normally simple program conversion.  It also occupies a whole lot of real estate.

 

Also - are there any plans in the works to allow the use of the new UniStream I/O with the Vision series - a UniStream version of the EX-RC1?

 

Joe T.

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Hi Joe,

 

I know it's not the answer you are looking for, but if real estate is the issue you might get a relatively easy result using a multi input signal condtioner.  It would be a toss up on extra wiring and complexity vs ability to use less I/Os.

 

A quick google brought up this pdf:  http://www.omega.com/Auto/pdf/he-x_series.pdf.

 

I'm sure there would be others around with more inputs available, but regardless even this 8 channel one would use much less space as you would likely get 3 conditioners on the rail space of one DI8.

 

Or perhaps you could use a gang of pheonix singles or similar, or a mini relay module to do much the same thing?

 

cheers,

 

Aus

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I am with Joe on the desire to have real 120VAC capability brought more into the main stream of Unitronics products.

 

 Unitronics is the only PLC manufacturer we work with that has no real 120VAC capability.  No AC input snap I/O modules, no 16 or 32 channel AC input add on modules and no triac output capabilities at all.  There are industry segments I would like to use Unitronics on but am destined never do so because of the cost to get AC I/O and the amount of space required to package the I/O.

 

How about a nice V200-18-E6B module repurposed to have AC inputs and leave everything else the same if possible, the addition of a 16 input module, and 16 triac output module . There are literally millions of burner, boiler, furnace, flare, thermal oxidizer, impingement, ..............ETC application installations that do not use DC voltage for any of their shutdowns .........everything is 120VAC.  The industries that use any of the US providers of flame safety equipment are always going to be 120VAC and will never ever change to 24 VDC.  Even if you are making a custom DCS system from scratch there isa need to have AC I/O.

 

The financial benefits to expanding Unitronics' capabilities to include 120VAC would be huge. 

 

My humble opinion

Keith

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  • 1 month later...
  • 5 weeks later...

Hey All,

Just to throw my two cents in along with Joe and Keith......

I work in an industry where we have a multitude of small “single purpose” machines that are placed into a production line, the setup varies from day to day depending on the product being produced.

Many of these machines were once old  120V relay control that at one point or another were modernized using some basic "brick” style PLC. As all things become obsolete, I find myself further updating their controls trying to bring them into the 21st century.
Most of these machines have just a handful of I/O, and limited logic which could easily be updated using “smart relays”. But, I really like using the Unitronics products (thank you Joe for introducing me to them years back). and find myself using the M91‘s or V120‘s depending on how much processing power I need. Even if I don’t really need an HMI, I find myself incorporating it, if nothing more than a troubleshooting resource for the other technicians.

But likewise, I have been frustrated with the lack of 120VAC I/O, making what could have been  a simple retrofit a bit more cumbersome, either interfacing between voltage levels or just completely replacing/rewiring everything to 24vdc.

While Joe and Keith leaned more towards the Snap I/O and remote modules, I would vote for updating even the smaller OPLC’s to a 120VAC I//O option. AS Keith points out, there are literally millions of control applications that live in the 120VAC world.

Regards,
JohnR

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Can I just add a vote from the non-US lands - can you consider a design that will handle 240VAC as well as 120VAC?

 

I don't see a huge demand, and it's often not a big deal to use interposing relays, and customers like to "upgrade" from 240VAC logic to 24VDC logic because it is safer.  But if the cost of increasing the voltage rating is not high then it will make the module more universal.

 

It is frustrating to see a potential solution then find out it only accepts 120V.

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Can I just add a vote from the non-US lands - can you consider a design that will handle 240VAC as well as 120VAC?

 

I don't see a huge demand, and it's often not a big deal to use interposing relays, and customers like to "upgrade" from 240VAC logic to 24VDC logic because it is safer.  But if the cost of increasing the voltage rating is not high then it will make the module more universal.

 

It is frustrating to see a potential solution then find out it only accepts 120V.

 

I'll 2nd that... 

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Hi;

I doubt that Unitronics will put TRAIC outputs in  t heir PLC's. All their designs are based on 24 VDC with some 12VDC units. - which makes then universally adaptable.

The Remote I/O    Ethernet based,  URB-TCP  do have  AC Solid State  Output modules.

Other option is  PNP outputs from the PLC and I/O   and use solid state relays.   ( more costs effective to replace a blown relay than a whole PLC.)

 

DanT

 

 

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+1 to what DanT says on the probability Unitronics will add triacs to their built-in IO units.

We always use transistor outputs driving a product like this:

https://cdn.findernet.com/app/uploads/2020/09/28100454/S39EN-2.pdf

It adds a bit of cost to the project but- 

On 3/12/2021 at 8:59 AM, DanT said:

more cost effective to replace a blown relay than a whole PLC.)

Definitely.  Especially during startup when you find improperly wired loads.

Joe T.

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