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External larger HMI's

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Has anyone successfully used an external HMI with a Vision series unit? We have a customer that wants the V570 in the dash of their truck, remote mounted expansion modules (nothing new there, we've done dozens of times in several different types of trucks), but they want an 8" or larger HMI outside the cab of the truck on a main control panel.

Yes? No? Good luck?

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Connecting to 3rd party HMI screens, either over serial or ethernet, is a relatively easy task.

The most common way to talk between our PLC and the external HMI is to use the MODBUS protocol (RTU or TCP) to transfer data.

Generally the Unitronics PLC will be the MODBUS slave and the 3rd party HMI will be the master polling.

If you look in the examples folder of VisiLogic you will find full working applications for implementing MODBUS with our PLC's.

FYI: We are releasing a 10.4" color touch screen PLC+HMI soon. (Vision 1040)

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That is good news on the larger display. Now for the next obvious question. When will the UL approval process start? I know it takes time, but I am salivating at the availability of these two new products, but I am unable to use non-UL listed components since almost all of my equipment panels require UL508A listings. Or if somone can answer the following question? It is my understanding that there is a clause in the UL508A labeling requirements, that as long as a product has not been rejected by UL, that a product that operates at 120 VAC or less can still be put in a UL 508a panel as long as ground fault protection is put in the power circuit that feeds the device that is not UL listed or recognized. I have seen this done one time before, but it was not done by me and as a general rule I have always fallen under the opinion that if ther is no UL or RU on the device (Ind. Cont. Eq.)

Anyone who can speak to this would be greatly appreciated.

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I have gotten an answer to my question on UL 508a from yesterday and the answer is as follows:

If an “unevaluated component†that uses 120 VAC or less is desired to be used in a UL508a panel then it can be used provided that there are certain precautions that are taken (this would apply to snap IO and remote IO as well as PLC/HMI combo units) then the product can be used if:

1) The power circuit feeding the “unevaluated product†has an isolation transformer with 2 primary fuses and 1 secondary fuse and the neutral of the secondary side is bonded to earth ground.

2) Either an approved class A ground fault receptacle or a class a (6ma trip) circuit breaker and ground fault circuit interrupter (CBGFCI) must be installed to feed power to the “unevaluated productâ€

3) Discrete inputs that carry greater than 30Vrms must have an UL listed interposing relay placed on each input line

4) Discrete inputs that carry less than 30Vrms require no additional protection (so Unitronics DC inputs are all ok as is)

5) Discrete outputs that carry greater than 30Vrms must have an UL listed interposing relay placed on each output line

6) Discrete outputs that carry less than 30Vrms and the power source is inside the listed enclosure require no additional protection

7) Discrete outputs that carry less than 30Vrms and the power source is outside the listed enclosure require a .5 amp fuse placed on each output line

8) Sensing devices such as “transducer, tachometer, thermocouple, or similar feedback device†no additional protection is required.

I have paraphrased the information so do not use the above information as a how to guide and only as a discussion on the ability to install no Ul product in a Ul 508a cabinet.

I have left out the information on the multitude of marking labels that must also be provided and the special markings on electrical drawings but you get the idea. The use of the device is predicated that the device has never been evaluated and denied a UL listing or UL recognized status. This is good news for me in that I can use the New V560 and the upcoming 1040 and other products that have either not been submitted to UL or had the UL process completed. It is more work and more costly to use the non UL products due to the requirements listed above, but they can be used (I have been looking for a way to be able to use the new V560) and that makes me happy J

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Right now I'm developing an application with a V350 and a HMI FUJI ELECTRIC HAKKO MONITOUCH V815 .

The V815 of Fuji is a 15" screen and it connect with Unitronics with PCOM protocol serial or ethernet. If I use the driver Unitronics or UnitronicsTCP I can read and write directly MI, MB, ML, DW,... all but X operands.

Before I used Modbus TCP, but now it is easier.

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